From 09d3670df3e4593be1d2299a62d982829016b847 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 31 Jul 2006 20:09:10 +0000 Subject: Change the relation_open protocol so that we obtain lock on a relation (table or index) before trying to open its relcache entry. This fixes race conditions in which someone else commits a change to the relation's catalog entries while we are in process of doing relcache load. Problems of that ilk have been reported sporadically for years, but it was not really practical to fix until recently --- for instance, the recent addition of WAL-log support for in-place updates helped. Along the way, remove pg_am.amconcurrent: all AMs are now expected to support concurrent update. --- src/backend/commands/cluster.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'src/backend/commands/cluster.c') diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index e16afa0559d..f0cbaefd60e 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -11,7 +11,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/cluster.c,v 1.151 2006/07/31 01:16:37 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/cluster.c,v 1.152 2006/07/31 20:09:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -314,8 +314,7 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid, bool recheck) { Relation OldIndex; - OldIndex = index_open(indexOid); - LockRelation(OldIndex, AccessExclusiveLock); + OldIndex = index_open(indexOid, AccessExclusiveLock); /* * Check that index is in fact an index on the given relation @@ -406,7 +405,7 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid, bool recheck) errmsg("cannot cluster temporary tables of other sessions"))); /* Drop relcache refcnt on OldIndex, but keep lock */ - index_close(OldIndex); + index_close(OldIndex, NoLock); } /* @@ -649,7 +648,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex) */ NewHeap = heap_open(OIDNewHeap, AccessExclusiveLock); OldHeap = heap_open(OIDOldHeap, AccessExclusiveLock); - OldIndex = index_open(OIDOldIndex); + OldIndex = index_open(OIDOldIndex, AccessExclusiveLock); /* * Their tuple descriptors should be exactly alike, but here we only need @@ -669,7 +668,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex) * Scan through the OldHeap on the OldIndex and copy each tuple into the * NewHeap. */ - scan = index_beginscan(OldHeap, OldIndex, true, + scan = index_beginscan(OldHeap, OldIndex, SnapshotNow, 0, (ScanKey) NULL); while ((tuple = index_getnext(scan, ForwardScanDirection)) != NULL) @@ -724,7 +723,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex) pfree(values); pfree(nulls); - index_close(OldIndex); + index_close(OldIndex, NoLock); heap_close(OldHeap, NoLock); heap_close(NewHeap, NoLock); } -- cgit v1.2.3