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* [PATCH 3/5] 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 3463b42438..e33f92687c 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 503d64df38..a4b34ec570 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 45e1cfa56c..def0ad1dcf 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 d295d85cd2..745dfe9570 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11931,7 +11931,7 @@ 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;
@@ -17745,9 +17745,9 @@ 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 855076b1fd..321d2eb21e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -30,6 +30,7 @@
#include <unistd.h>
#include "access/commit_ts.h"
+#include "access/toast_compression.h"
#include "access/gin.h"
#include "access/rmgr.h"
#include "access/tableam.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 1de3ae2646..12ab404900 100644
--- a/src/test/regress/expected/compression.out
+++ b/src/test/regress/expected/compression.out
@@ -211,6 +211,22 @@ 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 2999b3bb79..cc9b913418 100644
--- a/src/test/regress/expected/compression_1.out
+++ b/src/test/regress/expected/compression_1.out
@@ -208,6 +208,25 @@ 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 ab35f3b4ae..0d5a2231d0 100644
--- a/src/test/regress/sql/compression.sql
+++ b/src/test/regress/sql/compression.sql
@@ -92,6 +92,14 @@ 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
--nHwqXXcoX0o6fKCv
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="0004-Alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: Fix typo in code comment
@ 2026-01-04 09:24 Chao Li <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Chao Li @ 2026-01-04 09:24 UTC (permalink / raw)
To: kelan <[email protected]>; +Cc: PostgreSQL Hackers <[email protected]>
> On Dec 31, 2025, at 09:10, kelan <[email protected]> wrote:
>
> Hi hickers,
> I fixed a comment error in the `WaitForParallelWorkersToFinish` function. The original comment was "In that case, or latch should have been set as well...", where I think "or" is a typo and it should be "our".
>
> --
> Best regards,
> Ke Lan
> Email:[email protected]
>
> <v1-0001-correct-typos-in-the-code-comments.patch>
Looking at the context, “or” doesn’t make sense here. Both “the” and “our” would work grammatically, and given the intent of the comment, “our” seems the most likely original wording.
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
^ permalink raw reply [nested|flat] 2+ messages in thread
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2021-03-10 08:35 [PATCH 3/5] Add default_toast_compression GUC Dilip Kumar <[email protected]>
2026-01-04 09:24 Re: Fix typo in code comment Chao Li <[email protected]>
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