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* [PATCH 6/8] Add default_toast_compression GUC
@ 2021-03-10 08:35 Dilip Kumar <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Dilip Kumar @ 2021-03-10 08:35 UTC (permalink / raw)
Justin Pryzby and Dilip Kumar
---
src/backend/access/common/toast_compression.c | 46 +++++++++++++++++++
src/backend/access/common/tupdesc.c | 2 +-
src/backend/bootstrap/bootstrap.c | 2 +-
src/backend/commands/tablecmds.c | 8 ++--
src/backend/utils/misc/guc.c | 12 +++++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/access/toast_compression.h | 22 ++++++++-
src/test/regress/expected/compression.out | 16 +++++++
src/test/regress/expected/compression_1.out | 19 ++++++++
src/test/regress/sql/compression.sql | 8 ++++
10 files changed, 128 insertions(+), 8 deletions(-)
diff --git a/src/backend/access/common/toast_compression.c b/src/backend/access/common/toast_compression.c
index db4911ce43..27fe47b201 100644
--- a/src/backend/access/common/toast_compression.c
+++ b/src/backend/access/common/toast_compression.c
@@ -55,6 +55,9 @@ const CompressionRoutine toast_compression[] =
}
};
+/* Compile-time default */
+char *default_toast_compression = DEFAULT_TOAST_COMPRESSION;
+
/*
* pglz_cmcompress - compression routine for pglz compression method
*
@@ -306,3 +309,46 @@ GetCompressionRoutines(char method)
{
return &toast_compression[CompressionMethodToId(method)];
}
+
+/* check_hook: validate new default_toast_compression */
+bool
+check_default_toast_compression(char **newval, void **extra, GucSource source)
+{
+ if (**newval == '\0')
+ {
+ GUC_check_errdetail("%s cannot be empty.",
+ "default_toast_compression");
+ return false;
+ }
+
+ if (strlen(*newval) >= NAMEDATALEN)
+ {
+ GUC_check_errdetail("%s is too long (maximum %d characters).",
+ "default_toast_compression", NAMEDATALEN - 1);
+ return false;
+ }
+
+ if (!CompressionMethodIsValid(CompressionNameToMethod(*newval)))
+ {
+ /*
+ * When source == PGC_S_TEST, don't throw a hard error for a
+ * nonexistent compression method, only a NOTICE. See comments in
+ * guc.h.
+ */
+ if (source == PGC_S_TEST)
+ {
+ ereport(NOTICE,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("compression method \"%s\" does not exist",
+ *newval)));
+ }
+ else
+ {
+ GUC_check_errdetail("Compression method \"%s\" does not exist.",
+ *newval);
+ return false;
+ }
+ }
+
+ return true;
+}
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index a66d1113db..362a371a6c 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -668,7 +668,7 @@ TupleDescInitEntry(TupleDesc desc,
att->attcollation = typeForm->typcollation;
if (IsStorageCompressible(typeForm->typstorage))
- att->attcompression = DefaultCompressionMethod;
+ att->attcompression = GetDefaultToastCompression();
else
att->attcompression = InvalidCompressionMethod;
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index af0c0aa77e..9be0841d08 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -733,7 +733,7 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
attrtypes[attnum]->atttypmod = -1;
attrtypes[attnum]->attislocal = true;
if (IsStorageCompressible(attrtypes[attnum]->attstorage))
- attrtypes[attnum]->attcompression = DefaultCompressionMethod;
+ attrtypes[attnum]->attcompression = GetDefaultToastCompression();
else
attrtypes[attnum]->attcompression = InvalidCompressionMethod;
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index e20dd5f63c..a0d2af0cde 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11971,7 +11971,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
if (!IsStorageCompressible(tform->typstorage))
attTup->attcompression = InvalidCompressionMethod;
else if (!CompressionMethodIsValid(attTup->attcompression))
- attTup->attcompression = DefaultCompressionMethod;
+ attTup->attcompression = GetDefaultToastCompression();
}
else
attTup->attcompression = InvalidCompressionMethod;
@@ -17847,9 +17847,9 @@ GetAttributeCompression(Form_pg_attribute att, char *compression)
/* fallback to default compression if it's not specified */
if (compression == NULL)
- return DefaultCompressionMethod;
-
- cmethod = CompressionNameToMethod(compression);
+ cmethod = GetDefaultToastCompression();
+ else
+ cmethod = CompressionNameToMethod(compression);
return cmethod;
}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 953837085f..e59ed5b214 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -33,6 +33,7 @@
#include "access/gin.h"
#include "access/rmgr.h"
#include "access/tableam.h"
+#include "access/toast_compression.h"
#include "access/transam.h"
#include "access/twophase.h"
#include "access/xact.h"
@@ -3915,6 +3916,17 @@ static struct config_string ConfigureNamesString[] =
check_default_table_access_method, NULL, NULL
},
+ {
+ {"default_toast_compression", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Sets the default compression for new columns."),
+ NULL,
+ GUC_IS_NAME
+ },
+ &default_toast_compression,
+ DEFAULT_TOAST_COMPRESSION,
+ check_default_toast_compression, NULL, NULL
+ },
+
{
{"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default tablespace to create tables and indexes in."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index f46c2dd7a8..7d7a433dcc 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -659,6 +659,7 @@
#temp_tablespaces = '' # a list of tablespace names, '' uses
# only default tablespace
#default_table_access_method = 'heap'
+#default_toast_compression = 'pglz' # 'pglz' or 'lz4'
#check_function_bodies = on
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
diff --git a/src/include/access/toast_compression.h b/src/include/access/toast_compression.h
index 38800cb97a..e9d9ce5634 100644
--- a/src/include/access/toast_compression.h
+++ b/src/include/access/toast_compression.h
@@ -15,6 +15,14 @@
#include "postgres.h"
+#include "utils/guc.h"
+
+/* default compression method if not specified. */
+#define DEFAULT_TOAST_COMPRESSION "pglz"
+
+/* GUCs */
+extern char *default_toast_compression;
+
/*
* Built-in compression methods. pg_attribute will store this in the
* attcompression column.
@@ -36,8 +44,6 @@ typedef enum CompressionId
LZ4_COMPRESSION_ID = 1
} CompressionId;
-/* use default compression method if it is not specified. */
-#define DefaultCompressionMethod PGLZ_COMPRESSION
#define IsValidCompression(cm) ((cm) != InvalidCompressionMethod)
#define IsStorageCompressible(storage) ((storage) != TYPSTORAGE_PLAIN && \
@@ -67,6 +73,8 @@ typedef struct CompressionRoutine
extern char CompressionNameToMethod(char *compression);
extern const CompressionRoutine *GetCompressionRoutines(char method);
+extern bool check_default_toast_compression(char **newval, void **extra,
+ GucSource source);
/*
* CompressionMethodToId - Convert compression method to compression id.
@@ -115,5 +123,15 @@ GetCompressionMethodName(char method)
return GetCompressionRoutines(method)->cmname;
}
+/*
+ * GetDefaultToastCompression -- get the current toast compression
+ *
+ * This exists to hide the use of the default_toast_compression GUC variable.
+ */
+static inline char
+GetDefaultToastCompression(void)
+{
+ return CompressionNameToMethod(default_toast_compression);
+}
#endif /* TOAST_COMPRESSION_H */
diff --git a/src/test/regress/expected/compression.out b/src/test/regress/expected/compression.out
index 6981d580dc..9ddffc8b18 100644
--- a/src/test/regress/expected/compression.out
+++ b/src/test/regress/expected/compression.out
@@ -231,6 +231,22 @@ CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
NOTICE: merging column "f1" with inherited definition
ERROR: column "f1" has a compression method conflict
DETAIL: pglz versus lz4
+-- test default_toast_compression GUC
+SET default_toast_compression = '';
+ERROR: invalid value for parameter "default_toast_compression": ""
+DETAIL: default_toast_compression cannot be empty.
+SET default_toast_compression = 'I do not exist compression';
+ERROR: invalid value for parameter "default_toast_compression": "I do not exist compression"
+DETAIL: Compression method "I do not exist compression" does not exist.
+SET default_toast_compression = 'lz4';
+DROP TABLE cmdata2;
+CREATE TABLE cmdata2 (f1 text);
+\d+ cmdata2
+ Table "public.cmdata2"
+ Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1 | text | | | | extended | lz4 | |
+
-- check data is ok
SELECT length(f1) FROM cmdata;
length
diff --git a/src/test/regress/expected/compression_1.out b/src/test/regress/expected/compression_1.out
index 893c18c7fa..03a7f46554 100644
--- a/src/test/regress/expected/compression_1.out
+++ b/src/test/regress/expected/compression_1.out
@@ -237,6 +237,25 @@ CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
NOTICE: merging column "f1" with inherited definition
ERROR: column "f1" has a compression method conflict
DETAIL: pglz versus lz4
+-- test default_toast_compression GUC
+SET default_toast_compression = '';
+ERROR: invalid value for parameter "default_toast_compression": ""
+DETAIL: default_toast_compression cannot be empty.
+SET default_toast_compression = 'I do not exist compression';
+ERROR: invalid value for parameter "default_toast_compression": "I do not exist compression"
+DETAIL: Compression method "I do not exist compression" does not exist.
+SET default_toast_compression = 'lz4';
+ERROR: unsupported LZ4 compression method
+DETAIL: This functionality requires the server to be built with lz4 support.
+HINT: You need to rebuild PostgreSQL using --with-lz4.
+DROP TABLE cmdata2;
+CREATE TABLE cmdata2 (f1 text);
+\d+ cmdata2
+ Table "public.cmdata2"
+ Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1 | text | | | | extended | pglz | |
+
-- check data is ok
SELECT length(f1) FROM cmdata;
length
diff --git a/src/test/regress/sql/compression.sql b/src/test/regress/sql/compression.sql
index b085c9fbd9..6c9b24f1f7 100644
--- a/src/test/regress/sql/compression.sql
+++ b/src/test/regress/sql/compression.sql
@@ -103,6 +103,14 @@ SELECT pg_column_compression(f1) FROM cmpart;
CREATE TABLE cminh() INHERITS(cmdata, cmdata1);
CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
+-- test default_toast_compression GUC
+SET default_toast_compression = '';
+SET default_toast_compression = 'I do not exist compression';
+SET default_toast_compression = 'lz4';
+DROP TABLE cmdata2;
+CREATE TABLE cmdata2 (f1 text);
+\d+ cmdata2
+
-- check data is ok
SELECT length(f1) FROM cmdata;
SELECT length(f1) FROM cmdata1;
--
2.17.0
--C94crkcyjafcjHxo
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="0007-Alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 2+ messages in thread
* REINDEX blocks virtually any queries but some prepared queries.
@ 2022-04-06 14:48 Frédéric Yhuel <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Frédéric Yhuel @ 2022-04-06 14:48 UTC (permalink / raw)
To: [email protected]
Hello,
From the documentation
(https://www.postgresql.org/docs/current/sql-reindex.html#id-1.9.3.162.7),
it sounds like REINDEX won't block read queries that don't need the
index. But it seems like the planner wants to take an ACCESS SHARE lock
on every indexes, regardless of the query, and so REINDEX actually
blocks any queries but some prepared queries whose plan have been cached.
I wonder if it is a bug, or if the documentation should be updated. What
do you think?
Here is a simple demo (tested with postgres 10 and master):
Session #1
===========================================================
srcpg@postgres=# CREATE TABLE flights (id INT generated always as
identity, takeoff DATE);
CREATE TABLE
srcpg@postgres=# INSERT INTO flights (takeoff) SELECT date '2022-03-01'
+ interval '1 day' * i FROM generate_series(1,1000) i;
INSERT 0 1000
srcpg@postgres=# CREATE INDEX ON flights(takeoff);
CREATE INDEX
srcpg@postgres=# BEGIN;
BEGIN
srcpg@postgres=# REINDEX INDEX flights_takeoff_idx ;
REINDEX
Session #2
===========================================================
srcpg@postgres=# SELECT pg_backend_pid();
pg_backend_pid
----------------
4114695
srcpg@postgres=# EXPLAIN SELECT id FROM flights;
--> it blocks
Session #3
===========================================================
srcpg@postgres=# SELECT locktype, relname, mode, granted FROM pg_locks
LEFT JOIN pg_class ON (oid = relation) WHERE pid = 4114695;
locktype | relname | mode | granted
------------+---------------------+-----------------+---------
virtualxid | ∅ | ExclusiveLock | t
relation | flights_takeoff_idx | AccessShareLock | f
relation | flights | AccessShareLock | t
^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2022-04-06 14:48 UTC | newest]
Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
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2021-03-10 08:35 [PATCH 6/8] Add default_toast_compression GUC Dilip Kumar <[email protected]>
2022-04-06 14:48 REINDEX blocks virtually any queries but some prepared queries. Frédéric Yhuel <[email protected]>
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