Arrange for VACUUM to delete the init file that relcache.c uses
to save a little bit of backend startup time. This way, the first backend started after a VACUUM will rebuild the init file with up-to-date statistics for the critical system indexes.
This commit is contained in:
Tom Lane
parent
f7d25d2ab6
commit
87d95ca04d
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.99 1999/04/12 16:56:36 vadim Exp $
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* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.100 1999/05/01 19:09:46 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -46,6 +46,7 @@
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#include "utils/inval.h"
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#include "utils/mcxt.h"
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#include "utils/portal.h"
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#include "utils/relcache.h"
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#include "utils/syscache.h"
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#ifndef HAVE_GETRUSAGE
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@ -219,7 +220,20 @@ vc_init()
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static void
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vc_shutdown()
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{
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/* on entry, not in a transaction */
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/* on entry, we are not in a transaction */
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/* Flush the init file that relcache.c uses to save startup time.
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* The next backend startup will rebuild the init file with up-to-date
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* information from pg_class. This lets the optimizer see the stats that
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* we've collected for certain critical system indexes. See relcache.c
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* for more details.
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*
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* Ignore any failure to unlink the file, since it might not be there
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* if no backend has been started since the last vacuum...
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*/
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unlink(RELCACHE_INIT_FILENAME);
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/* remove the vacuum cleaner lock file */
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if (unlink("pg_vlock") < 0)
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elog(ERROR, "vacuum: can't destroy lock file!");
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.59 1999/02/21 03:49:36 scrappy Exp $
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* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.60 1999/05/01 19:09:44 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -77,7 +77,6 @@
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#include "utils/memutils.h"
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#include "utils/rel.h"
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#include "utils/relcache.h"
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#include "utils/relcache.h"
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#include "utils/syscache.h"
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@ -87,13 +86,6 @@ static Relation RelationNameCacheGetRelation(char *relationName);
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static void init_irels(void);
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static void write_irels(void);
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/* ----------------
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* defines
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* ----------------
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*/
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#define private static
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#define INIT_FILENAME "pg_internal.init"
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/* ----------------
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* externs
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* ----------------
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@ -1826,11 +1818,20 @@ RelCheckFetch(Relation relation)
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* from an initialization file in the data/base/... directory.
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*
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* + If the initialization file isn't there, then we create the
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* relation descriptor using sequential scans and write it to
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* relation descriptors using sequential scans and write 'em to
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* the initialization file for use by subsequent backends.
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*
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* This is complicated and interferes with system changes, but
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* performance is so bad that we're willing to pay the tax.
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* We could dispense with the initialization file and just build the
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* critical reldescs the hard way on every backend startup, but that
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* slows down backend startup noticeably if pg_class is large.
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*
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* As of v6.5, vacuum.c deletes the initialization file at completion
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* of a VACUUM, so that it will be rebuilt at the next backend startup.
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* This ensures that vacuum-collected stats for the system indexes
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* will eventually get used by the optimizer --- otherwise the relcache
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* entries for these indexes will show zero sizes forever, since the
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* relcache entries are pinned in memory and will never be reloaded
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* from pg_class.
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*/
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/* pg_attnumind, pg_classnameind, pg_classoidind */
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@ -1852,9 +1853,9 @@ init_irels(void)
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int relno;
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#ifndef __CYGWIN32__
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if ((fd = FileNameOpenFile(INIT_FILENAME, O_RDONLY, 0600)) < 0)
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if ((fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_RDONLY, 0600)) < 0)
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#else
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if ((fd = FileNameOpenFile(INIT_FILENAME, O_RDONLY | O_BINARY, 0600)) < 0)
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if ((fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_RDONLY | O_BINARY, 0600)) < 0)
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#endif
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{
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write_irels();
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@ -2017,12 +2018,12 @@ write_irels(void)
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RelationBuildDescInfo bi;
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#ifndef __CYGWIN32__
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fd = FileNameOpenFile(INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC, 0600);
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fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC, 0600);
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#else
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fd = FileNameOpenFile(INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0600);
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fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0600);
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#endif
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if (fd < 0)
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elog(FATAL, "cannot create init file %s", INIT_FILENAME);
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elog(FATAL, "cannot create init file %s", RELCACHE_INIT_FILENAME);
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FileSeek(fd, 0L, SEEK_SET);
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@ -6,7 +6,7 @@
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: relcache.h,v 1.11 1999/02/13 23:22:31 momjian Exp $
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* $Id: relcache.h,v 1.12 1999/05/01 19:09:43 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -34,4 +34,10 @@ extern void RelationRegisterRelation(Relation relation);
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extern void RelationPurgeLocalRelation(bool xactComitted);
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extern void RelationInitialize(void);
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/*
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* both vacuum.c and relcache.c need to know the name of the relcache init file
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*/
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#define RELCACHE_INIT_FILENAME "pg_internal.init"
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#endif /* RELCACHE_H */
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