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[PATCH 6/8] Add default_toast_compression GUC 2+ messages / 2 participants [nested] [flat]
* [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
* [PATCH v35 3/5] Move conversion of a "historic" to MVCC snapshot to a separate function. @ 2026-02-16 19:49 Antonin Houska <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Antonin Houska @ 2026-02-16 19:49 UTC (permalink / raw) The conversion is now handled by SnapBuildMVCCFromHistoric(). REPACK CONCURRENTLY will also need it. --- src/backend/replication/logical/snapbuild.c | 59 +++++++++++++++++---- src/backend/utils/time/snapmgr.c | 3 +- src/include/replication/snapbuild.h | 1 + src/include/utils/snapmgr.h | 1 + 4 files changed, 52 insertions(+), 12 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index 7f79621b57e..a738ad8a864 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -440,10 +440,7 @@ Snapshot SnapBuildInitialSnapshot(SnapBuild *builder) { Snapshot snap; - TransactionId xid; TransactionId safeXid; - TransactionId *newxip; - int newxcnt = 0; Assert(XactIsoLevel == XACT_REPEATABLE_READ); Assert(builder->building_full_snapshot); @@ -485,7 +482,35 @@ SnapBuildInitialSnapshot(SnapBuild *builder) MyProc->xmin = snap->xmin; - /* allocate in transaction context */ + /* Convert the historic snapshot to MVCC snapshot. */ + return SnapBuildMVCCFromHistoric(snap, true); +} + +/* + * Turn a historic MVCC snapshot into an ordinary MVCC snapshot. + * + * Unlike a regular (non-historic) MVCC snapshot, the 'xip' array of this + * snapshot contains not only running main transactions, but also their + * subtransactions. On the other hand, 'subxip' will usually be empty. This + * difference does not affect the result of XidInMVCCSnapshot() because it + * searches both in 'xip' and 'subxip'. + * + * Pass true for 'in_place' if you don't care about modifying the source + * snapshot. If you need a new instance, and one that was allocated as a + * single chunk of memory, pass false. + */ +Snapshot +SnapBuildMVCCFromHistoric(Snapshot snapshot, bool in_place) +{ + TransactionId xid; + TransactionId *oldxip = snapshot->xip; + uint32 oldxcnt = snapshot->xcnt; + TransactionId *newxip; + int newxcnt = 0; + Snapshot result; + + Assert(snapshot->snapshot_type == SNAPSHOT_HISTORIC_MVCC); + newxip = palloc_array(TransactionId, GetMaxSnapshotXidCount()); /* @@ -494,7 +519,7 @@ SnapBuildInitialSnapshot(SnapBuild *builder) * classical snapshot by marking all non-committed transactions as * in-progress. This can be expensive. */ - for (xid = snap->xmin; NormalTransactionIdPrecedes(xid, snap->xmax);) + for (xid = snapshot->xmin; NormalTransactionIdPrecedes(xid, snapshot->xmax);) { void *test; @@ -502,7 +527,7 @@ SnapBuildInitialSnapshot(SnapBuild *builder) * Check whether transaction committed using the decoding snapshot * meaning of ->xip. */ - test = bsearch(&xid, snap->xip, snap->xcnt, + test = bsearch(&xid, snapshot->xip, snapshot->xcnt, sizeof(TransactionId), xidComparator); if (test == NULL) @@ -519,11 +544,25 @@ SnapBuildInitialSnapshot(SnapBuild *builder) } /* adjust remaining snapshot fields as needed */ - snap->snapshot_type = SNAPSHOT_MVCC; - snap->xcnt = newxcnt; - snap->xip = newxip; + snapshot->xcnt = newxcnt; + snapshot->xip = newxip; - return snap; + if (in_place) + result = snapshot; + else + { + result = CopySnapshot(snapshot); + + /* Restore the original values so the source is intact. */ + snapshot->xip = oldxip; + snapshot->xcnt = oldxcnt; + + /* newxip has been copied */ + pfree(newxip); + } + result->snapshot_type = SNAPSHOT_MVCC; + + return result; } /* diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c index 2e6197f5f35..3af1b366adf 100644 --- a/src/backend/utils/time/snapmgr.c +++ b/src/backend/utils/time/snapmgr.c @@ -213,7 +213,6 @@ typedef struct ExportedSnapshot static List *exportedSnapshots = NIL; /* Prototypes for local functions */ -static Snapshot CopySnapshot(Snapshot snapshot); static void UnregisterSnapshotNoOwner(Snapshot snapshot); static void FreeSnapshot(Snapshot snapshot); static void SnapshotResetXmin(void); @@ -604,7 +603,7 @@ SetTransactionSnapshot(Snapshot sourcesnap, VirtualTransactionId *sourcevxid, * The copy is palloc'd in TopTransactionContext and has initial refcounts set * to 0. The returned snapshot has the copied flag set. */ -static Snapshot +Snapshot CopySnapshot(Snapshot snapshot) { Snapshot newsnap; diff --git a/src/include/replication/snapbuild.h b/src/include/replication/snapbuild.h index ccded021433..34383dea776 100644 --- a/src/include/replication/snapbuild.h +++ b/src/include/replication/snapbuild.h @@ -73,6 +73,7 @@ extern void FreeSnapshotBuilder(SnapBuild *builder); extern void SnapBuildSnapDecRefcount(Snapshot snap); extern Snapshot SnapBuildInitialSnapshot(SnapBuild *builder); +extern Snapshot SnapBuildMVCCFromHistoric(Snapshot snapshot, bool in_place); extern const char *SnapBuildExportSnapshot(SnapBuild *builder); extern void SnapBuildClearExportedSnapshot(void); extern void SnapBuildResetExportedSnapshotState(void); diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h index b8c01a291a1..de824945f0b 100644 --- a/src/include/utils/snapmgr.h +++ b/src/include/utils/snapmgr.h @@ -63,6 +63,7 @@ extern Snapshot GetTransactionSnapshot(void); extern Snapshot GetLatestSnapshot(void); extern void SnapshotSetCommandId(CommandId curcid); +extern Snapshot CopySnapshot(Snapshot snapshot); extern Snapshot GetCatalogSnapshot(Oid relid); extern Snapshot GetNonHistoricCatalogSnapshot(Oid relid); extern void InvalidateCatalogSnapshot(void); -- 2.47.3 --kmtyk4ln3767qrma Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename="v35-0004-Add-CONCURRENTLY-option-to-REPACK-command.patch" ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2026-02-16 19:49 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2021-03-10 08:35 [PATCH 6/8] Add default_toast_compression GUC Dilip Kumar <[email protected]> 2026-02-16 19:49 [PATCH v35 3/5] Move conversion of a "historic" to MVCC snapshot to a separate function. Antonin Houska <[email protected]>
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