On Mon, May 20, 2013 at 3:11 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> Armand du Plessis <a...@bank.io> writes: > > The autovacuum completed (after many hours) however it didn't seem to > have > > frozen any old pages as it just kicks off again right away with the same > > reason (VACUUM ANALYZE public.messages (to prevent wraparound)) > > I suspect it's unable to move the table's min XID forward at all because > there is some old open transaction preventing cleanup of very old dead > tuples. Look for old xact_start times in pg_stat_activity. Also look > for old entries in pg_prepared_xacts. If you find any, get rid of them. > Thanks Tom, that sounds like it possibly could've caused it. I've since restarted the cluster (kicking myself) so there's no old transactions left in either table. (pg_prepared_xacts is actually empty). Will check there first if this happens again. > regards, tom lane >
