diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/commands/vacuum.c | 18 | ||||
| -rw-r--r-- | src/backend/utils/cache/relcache.c | 35 |
2 files changed, 34 insertions, 19 deletions
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index dcb3365a7ba..757580ccbe8 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.99 1999/04/12 16:56:36 vadim Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.100 1999/05/01 19:09:46 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -46,6 +46,7 @@ #include "utils/inval.h" #include "utils/mcxt.h" #include "utils/portal.h" +#include "utils/relcache.h" #include "utils/syscache.h" #ifndef HAVE_GETRUSAGE @@ -219,7 +220,20 @@ vc_init() static void vc_shutdown() { - /* on entry, not in a transaction */ + /* on entry, we are not in a transaction */ + + /* Flush the init file that relcache.c uses to save startup time. + * The next backend startup will rebuild the init file with up-to-date + * information from pg_class. This lets the optimizer see the stats that + * we've collected for certain critical system indexes. See relcache.c + * for more details. + * + * Ignore any failure to unlink the file, since it might not be there + * if no backend has been started since the last vacuum... + */ + unlink(RELCACHE_INIT_FILENAME); + + /* remove the vacuum cleaner lock file */ if (unlink("pg_vlock") < 0) elog(ERROR, "vacuum: can't destroy lock file!"); diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index 464d94021a6..38edc3a790a 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.59 1999/02/21 03:49:36 scrappy Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.60 1999/05/01 19:09:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -77,7 +77,6 @@ #include "utils/memutils.h" #include "utils/rel.h" #include "utils/relcache.h" -#include "utils/relcache.h" #include "utils/syscache.h" @@ -88,13 +87,6 @@ static void init_irels(void); static void write_irels(void); /* ---------------- - * defines - * ---------------- - */ -#define private static -#define INIT_FILENAME "pg_internal.init" - -/* ---------------- * externs * ---------------- */ @@ -1826,11 +1818,20 @@ RelCheckFetch(Relation relation) * from an initialization file in the data/base/... directory. * * + If the initialization file isn't there, then we create the - * relation descriptor using sequential scans and write it to + * relation descriptors using sequential scans and write 'em to * the initialization file for use by subsequent backends. * - * This is complicated and interferes with system changes, but - * performance is so bad that we're willing to pay the tax. + * We could dispense with the initialization file and just build the + * critical reldescs the hard way on every backend startup, but that + * slows down backend startup noticeably if pg_class is large. + * + * As of v6.5, vacuum.c deletes the initialization file at completion + * of a VACUUM, so that it will be rebuilt at the next backend startup. + * This ensures that vacuum-collected stats for the system indexes + * will eventually get used by the optimizer --- otherwise the relcache + * entries for these indexes will show zero sizes forever, since the + * relcache entries are pinned in memory and will never be reloaded + * from pg_class. */ /* pg_attnumind, pg_classnameind, pg_classoidind */ @@ -1852,9 +1853,9 @@ init_irels(void) int relno; #ifndef __CYGWIN32__ - if ((fd = FileNameOpenFile(INIT_FILENAME, O_RDONLY, 0600)) < 0) + if ((fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_RDONLY, 0600)) < 0) #else - if ((fd = FileNameOpenFile(INIT_FILENAME, O_RDONLY | O_BINARY, 0600)) < 0) + if ((fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_RDONLY | O_BINARY, 0600)) < 0) #endif { write_irels(); @@ -2017,12 +2018,12 @@ write_irels(void) RelationBuildDescInfo bi; #ifndef __CYGWIN32__ - fd = FileNameOpenFile(INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC, 0600); + fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC, 0600); #else - fd = FileNameOpenFile(INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0600); + fd = FileNameOpenFile(RELCACHE_INIT_FILENAME, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0600); #endif if (fd < 0) - elog(FATAL, "cannot create init file %s", INIT_FILENAME); + elog(FATAL, "cannot create init file %s", RELCACHE_INIT_FILENAME); FileSeek(fd, 0L, SEEK_SET); |