mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2024-12-09 08:10:09 +08:00
Code Issues Packages Projects Releases Wiki Activity

Small performance improvement --- use indexscan not heapscan to find

Browse Source 
pg_statistic rows to delete while dropping a relation.
This commit is contained in:
Tom Lane 2002-07-19 22:21:17 +00:00
parent 59a471fc4c
commit 009d593c48
1 changed files with 13 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
src/backend/catalog/heap.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.210 2002/07/18 16:47:22 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.211 2002/07/19 22:21:17 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -793,7 +793,8 @@ heap_create_with_catalog(const char *relname,
* Formerly, this routine checked for child relations and aborted the
* deletion if any were found. Now we rely on the dependency mechanism
* to check for or delete child relations. By the time we get here,
* there are no children and we need only remove the pg_inherits rows.
* there are no children and we need only remove any pg_inherits rows
* linking this relation to its parent(s).
*/
static void
RelationRemoveInheritance(Relation relation)
@ -1743,21 +1744,25 @@ static void
RemoveStatistics(Relation rel)
{
Relation pgstatistic;
HeapScanDesc scan;
SysScanDesc scan;
ScanKeyData key;
HeapTuple tuple;
pgstatistic = heap_openr(StatisticRelationName, RowExclusiveLock);
ScanKeyEntryInitialize(&key, 0x0, Anum_pg_statistic_starelid,
F_OIDEQ,
ScanKeyEntryInitialize(&key, 0x0,
Anum_pg_statistic_starelid, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = heap_beginscan(pgstatistic, SnapshotNow, 1, &key);
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
scan = systable_beginscan(pgstatistic, StatisticRelidAttnumIndex, true,
SnapshotNow, 1, &key);
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
{
simple_heap_delete(pgstatistic, &tuple->t_self);
}
heap_endscan(scan);
systable_endscan(scan);
heap_close(pgstatistic, RowExclusiveLock);
}