diff options
| -rw-r--r-- | src/backend/catalog/toasting.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c index b059f9d784b..f2b4b62837e 100644 --- a/src/backend/catalog/toasting.c +++ b/src/backend/catalog/toasting.c @@ -59,11 +59,13 @@ AlterTableCreateToastTable(Oid relOid, Datum reloptions) Relation rel; /* - * Grab a DDL-exclusive lock on the target table, since we'll update the - * pg_class tuple. This is redundant for all present users. Tuple - * toasting behaves safely in the face of a concurrent TOAST table add. + * Grab an exclusive lock on the target table, since we'll update its + * pg_class tuple. This is redundant for all present uses, since caller + * will have such a lock already. But the lock is needed to ensure that + * concurrent readers of the pg_class tuple won't have visibility issues, + * so let's be safe. */ - rel = heap_open(relOid, ShareUpdateExclusiveLock); + rel = heap_open(relOid, AccessExclusiveLock); /* create_toast_table does all the work */ (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions); |