*
*
* 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 $
*
*-------------------------------------------------------------------------
*/
#include "utils/inval.h"
#include "utils/mcxt.h"
#include "utils/portal.h"
+#include "utils/relcache.h"
#include "utils/syscache.h"
#ifndef HAVE_GETRUSAGE
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!");
*
*
* 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 $
*
*-------------------------------------------------------------------------
*/
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/relcache.h"
-#include "utils/relcache.h"
#include "utils/syscache.h"
static void write_irels(void);
/* ----------------
- * defines
- * ----------------
- */
-#define private static
-#define INIT_FILENAME "pg_internal.init"
-
-/* ----------------
* externs
* ----------------
*/
* 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 */
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();
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);