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A bunch of changes aimed at reducing backend startup time...

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Improve 'pg_internal.init' relcache entry preload mechanism so that it is
safe to use for all system catalogs, and arrange to preload a realistic
set of system-catalog entries instead of only the three nailed-in-cache
indexes that were formerly loaded this way.  Fix mechanism for deleting
out-of-date pg_internal.init files: this must be synchronized with transaction
commit, not just done at random times within transactions.  Drive it off
relcache invalidation mechanism so that no special-case tests are needed.

Cache additional information in relcache entries for indexes (their pg_index
tuples and index-operator OIDs) to eliminate repeated lookups.  Also cache
index opclass info at the per-opclass level to avoid repeated lookups during
relcache load.

Generalize 'systable scan' utilities originally developed by Hiroshi,
move them into genam.c, use in a number of places where there was formerly
ugly code for choosing either heap or index scan.  In particular this allows
simplification of the logic that prevents infinite recursion between syscache
and relcache during startup: we can easily switch to heapscans in relcache.c
when and where needed to avoid recursion, so IndexScanOK becomes simpler and
does not need any expensive initialization.

Eliminate useless opening of a heapscan data structure while doing an indexscan
(this saves an mdnblocks call and thus at least one kernel call).
This commit is contained in:
Tom Lane
2002-02-19 20:11:20 +00:00
parent 8e2998d8a6
commit 7863404417
33 changed files with 1997 additions and 2220 deletions
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42
src/backend/commands/vacuum.c
View File

@@ -13,7 +13,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.213 2002/01/06 00:37:44 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.214 2002/02/19 20:11:12 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -315,20 +315,6 @@ vacuum_shutdown(VacuumStmt *vacstmt)
vac_truncate_clog(initialOldestXmin, initialFreezeLimit);
}
/*
* If we did a complete vacuum or analyze, then 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.
*/
if (vacstmt->vacrel == NULL)
unlink(RELCACHE_INIT_FILENAME);
/*
* Clean up working storage --- note we must do this after
* StartTransactionCommand, else we might be trying to delete the
@@ -535,8 +521,15 @@ vac_update_relstats(Oid relid, BlockNumber num_pages, double num_tuples,
if (!hasindex)
pgcform->relhaspkey = false;
/* invalidate the tuple in the cache and write the buffer */
/*
* Invalidate the tuple in the catcaches; this also arranges to flush
* the relation's relcache entry. (If we fail to commit for some reason,
* no flush will occur, but no great harm is done since there are no
* noncritical state updates here.)
*/
RelationInvalidateHeapTuple(rd, &rtup);
/* Write the buffer */
WriteBuffer(buffer);
heap_close(rd, RowExclusiveLock);
@@ -2816,10 +2809,6 @@ vac_close_indexes(int nindexes, Relation *Irel)
bool
vac_is_partial_index(Relation indrel)
{
bool result;
HeapTuple cachetuple;
Form_pg_index indexStruct;
/*
* If the index's AM doesn't support nulls, it's partial for our
* purposes
@@ -2828,18 +2817,7 @@ vac_is_partial_index(Relation indrel)
return true;
/* Otherwise, look to see if there's a partial-index predicate */
cachetuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(RelationGetRelid(indrel)),
0, 0, 0);
if (!HeapTupleIsValid(cachetuple))
elog(ERROR, "vac_is_partial_index: index %u not found",
RelationGetRelid(indrel));
indexStruct = (Form_pg_index) GETSTRUCT(cachetuple);
result = (VARSIZE(&indexStruct->indpred) > VARHDRSZ);
ReleaseSysCache(cachetuple);
return result;
return (VARSIZE(&indrel->rd_index->indpred) > VARHDRSZ);
}