diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index b3d21875b25..639cd7296e2 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.257 2008/06/15 01:25:53 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.258 2008/06/15 16:29:05 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -676,6 +676,28 @@ RemoveRelations(DropStmt *drop) continue; } + /* + * In DROP INDEX, attempt to acquire lock on the parent table before + * locking the index. index_drop() will need this anyway, and since + * regular queries lock tables before their indexes, we risk deadlock + * if we do it the other way around. No error if we don't find a + * pg_index entry, though --- that most likely means it isn't an + * index, and we'll fail below. + */ + if (relkind == RELKIND_INDEX) + { + tuple = SearchSysCache(INDEXRELID, + ObjectIdGetDatum(relOid), + 0, 0, 0); + if (HeapTupleIsValid(tuple)) + { + Form_pg_index index = (Form_pg_index) GETSTRUCT(tuple); + + LockRelationOid(index->indrelid, AccessExclusiveLock); + ReleaseSysCache(tuple); + } + } + /* Get the lock before trying to fetch the syscache entry */ LockRelationOid(relOid, AccessExclusiveLock); |