Steven Flatt wrote:
> The bad thing, which I don't totally understand from reading the docs, is
> that another db-wide vacuum kicked off exactly 24 hours after the first
> db-wide vacuum kicked off, before the first one had finished. (Note that
> these vacuums seem to go through the tables alphabetically.) I managed to
> explain this to myself in that there were still rows in tables not yet
> touched by the first db-wide vacuum that could have XIDs older than
> autovacuum_freeze_max_age. Fine, so two db-wide vacuums were now taking
> place, one behind the other.
Are you sure there's no cron job starting the vacuums? 24h sounds too
good to be a coincidence, and there's no magic constant of 24h in the
autovacuum code. Besides, autovacuum can only be running one VACUUM at a
time, so there must be something else launching them.
What's your vacuuming strategy in general, before and after upgrade?
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com