From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Fri, 1 Feb 2013 15:00:40 +0000 (-0300)
Subject: Fix typo in freeze_table_age implementation
X-Git-Tag: REL9_2_3~6
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=231dbb3c9be755eebdf677b469f2dd4494e7937f;p=postgresql

Fix typo in freeze_table_age implementation

The original code used freeze_min_age instead of freeze_table_age.  The
main consequence of this mistake is that lowering freeze_min_age would
cause full-table scans to occur much more frequently, which causes
serious issues because the number of writes required is much larger.
That feature (freeze_min_age) is supposed to affect only how soon tuples
are frozen; some pages should still be skipped due to the visibility
map.

Backpatch to 8.4, where the freeze_table_age feature was introduced.

Report and patch from Andres Freund
---

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 9b5b79fdcc..656b90eed3 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -446,7 +446,7 @@ vacuum_set_xid_limits(int freeze_min_age,
 		 * VACUUM schedule, the nightly VACUUM gets a chance to freeze tuples
 		 * before anti-wraparound autovacuum is launched.
 		 */
-		freezetable = freeze_min_age;
+		freezetable = freeze_table_age;
 		if (freezetable < 0)
 			freezetable = vacuum_freeze_table_age;
 		freezetable = Min(freezetable, autovacuum_freeze_max_age * 0.95);