diff options
Diffstat (limited to 'src/backend/executor')
| -rw-r--r-- | src/backend/executor/execUtils.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c index c1b6e5d79a3..3777b68e64c 100644 --- a/src/backend/executor/execUtils.c +++ b/src/backend/executor/execUtils.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.60 2000/06/17 21:48:49 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.61 2000/06/19 23:40:47 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -799,15 +799,20 @@ ExecOpenIndices(RelationInfo *resultRelationInfo) /* ---------------- * Open (and lock, if necessary) the index relation * - * Hack for not btree and hash indices: they use relation - * level exclusive locking on update (i.e. - they are not - * ready for MVCC) and so we have to exclusively lock - * indices here to prevent deadlocks if we will scan them - * - index_beginscan places AccessShareLock, indices - * update methods don't use locks at all. We release this - * lock in ExecCloseIndices. Note, that hashes use page - * level locking - i.e. are not deadlock-free, - let's - * them be on their way -:)) vadim 03-12-1998 + * Hack for not btree and hash indices: they use relation level + * exclusive locking on update (i.e. - they are not ready for MVCC) + * and so we have to exclusively lock indices here to prevent + * deadlocks if we will scan them - index_beginscan places + * AccessShareLock, indices update methods don't use locks at all. + * We release this lock in ExecCloseIndices. Note, that hashes use + * page level locking - i.e. are not deadlock-free - let's them be + * on their way -:)) vadim 03-12-1998 + * + * If there are multiple not-btree-or-hash indices, all backends must + * lock the indices in the same order or we will get deadlocks here + * during concurrent updates. This is now guaranteed by + * RelationGetIndexList(), which promises to return the index list + * in OID order. tgl 06-19-2000 * ---------------- */ indexDesc = index_open(indexOid); |