diff options
Diffstat (limited to 'src/backend/commands/sequence.c')
| -rw-r--r-- | src/backend/commands/sequence.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c index 46103561c31..28f85222647 100644 --- a/src/backend/commands/sequence.c +++ b/src/backend/commands/sequence.c @@ -1777,11 +1777,8 @@ pg_sequence_last_value(PG_FUNCTION_ARGS) Oid relid = PG_GETARG_OID(0); SeqTable elm; Relation seqrel; - Buffer buf; - HeapTupleData seqtuple; - Form_pg_sequence_data seq; - bool is_called; - int64 result; + bool is_called = false; + int64 result = 0; /* open and lock sequence */ init_sequence(relid, &elm, &seqrel); @@ -1792,12 +1789,28 @@ pg_sequence_last_value(PG_FUNCTION_ARGS) errmsg("permission denied for sequence %s", RelationGetRelationName(seqrel)))); - seq = read_seq_tuple(seqrel, &buf, &seqtuple); + /* + * We return NULL for other sessions' temporary sequences. The + * pg_sequences system view already filters those out, but this offers a + * defense against ERRORs in case someone invokes this function directly. + * + * Also, for the benefit of the pg_sequences view, we return NULL for + * unlogged sequences on standbys instead of throwing an error. + */ + if (!RELATION_IS_OTHER_TEMP(seqrel) && + (RelationIsPermanent(seqrel) || !RecoveryInProgress())) + { + Buffer buf; + HeapTupleData seqtuple; + Form_pg_sequence_data seq; + + seq = read_seq_tuple(seqrel, &buf, &seqtuple); - is_called = seq->is_called; - result = seq->last_value; + is_called = seq->is_called; + result = seq->last_value; - UnlockReleaseBuffer(buf); + UnlockReleaseBuffer(buf); + } sequence_close(seqrel, NoLock); if (is_called) |