diff options
Diffstat (limited to 'src/backend/utils/time')
| -rw-r--r-- | src/backend/utils/time/tqual.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c index eedc6222be8..2bdb6d9e714 100644 --- a/src/backend/utils/time/tqual.c +++ b/src/backend/utils/time/tqual.c @@ -32,7 +32,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.98 2006/10/04 00:30:04 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.99 2006/11/05 22:42:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1099,9 +1099,11 @@ HeapTupleSatisfiesVacuum(HeapTupleHeader tuple, TransactionId OldestXmin, { /* * "Deleting" xact really only locked it, so the tuple is live in any - * case. However, we must make sure that either XMAX_COMMITTED or - * XMAX_INVALID gets set once the xact is gone; otherwise it is unsafe - * to recycle CLOG status after vacuuming. + * case. However, we should make sure that either XMAX_COMMITTED or + * XMAX_INVALID gets set once the xact is gone, to reduce the costs + * of examining the tuple for future xacts. Also, marking dead + * MultiXacts as invalid here provides defense against MultiXactId + * wraparound (see also comments in heap_freeze_tuple()). */ if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED)) { |