diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index d9187a86c0e..f143101b5dc 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -9513,8 +9513,7 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) * appropriate work queue entries. We do this before dropping because in * the case of a FOREIGN KEY constraint, we might not yet have exclusive * lock on the table the constraint is attached to, and we need to get - * that before dropping. It's safe because the parser won't actually look - * at the catalogs to detect the existing entry. + * that before reparsing/dropping. * * We can't rely on the output of deparsing to tell us which relation to * operate on, because concurrent activity might have made the name @@ -9530,6 +9529,7 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) Form_pg_constraint con; Oid relid; Oid confrelid; + char contype; bool conislocal; tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId)); @@ -9538,6 +9538,7 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) con = (Form_pg_constraint) GETSTRUCT(tup); relid = con->conrelid; confrelid = con->confrelid; + contype = con->contype; conislocal = con->conislocal; ReleaseSysCache(tup); @@ -9550,6 +9551,15 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) if (!conislocal) continue; + /* + * When rebuilding an FK constraint that references the table we're + * modifying, we might not yet have any lock on the FK's table, so get + * one now. We'll need AccessExclusiveLock for the DROP CONSTRAINT + * step, so there's no value in asking for anything weaker. + */ + if (relid != tab->relid && contype == CONSTRAINT_FOREIGN) + LockRelationOid(relid, AccessExclusiveLock); + ATPostAlterTypeParse(oldId, relid, confrelid, (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); |