diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/storage/lmgr/predicate.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c index 46b86546ee0..11dede9e70b 100644 --- a/src/backend/storage/lmgr/predicate.c +++ b/src/backend/storage/lmgr/predicate.c @@ -3638,14 +3638,20 @@ CheckTargetForConflictsIn(PREDICATELOCKTARGETTAG *targettag) if (sxact == MySerializableXact) { /* - * If we're getting a write lock on the tuple, we don't need a - * predicate (SIREAD) lock. At this point our transaction already - * has an ExclusiveRowLock on the relation, so we are OK to drop - * the predicate lock on the tuple, if found, without fearing that - * another write against the tuple will occur before the MVCC - * information makes it to the buffer. + * If we're getting a write lock on the tuple and we're not in a + * subtransaction, we don't need a predicate (SIREAD) lock. We + * can't use this optimization within a subtransaction because + * the subtransaction could be rolled back, and we would be left + * without any lock at the top level. + * + * At this point our transaction already has an ExclusiveRowLock + * on the relation, so we are OK to drop the predicate lock on + * the tuple, if found, without fearing that another write + * against the tuple will occur before the MVCC information + * makes it to the buffer. */ - if (GET_PREDICATELOCKTARGETTAG_OFFSET(*targettag)) + if (!IsSubTransaction() + && GET_PREDICATELOCKTARGETTAG_OFFSET(*targettag)) { uint32 predlockhashcode; PREDICATELOCKTARGET *rmtarget = NULL; |