Tobias Brox <tobixen(at)gmail(dot)com> wrote:
> If it was to me, we would have had autovacuum turned on. We've
> had one bad experience when the autovacuumer decided to start
> vacuuming one of the biggest table at the worst possible moment -
> and someone figured autovacuum was a bad idea. I think we
> probably still would need regular vacuums to avoid that happening,
> but with autovacuum on, maybe we could have managed with regular
> vacuums only once a week or so.
Right, there's really no need to turn autovacuum off; if you hit it
during normal operations you've got enough bloat that it's going to
tend to start dragging down performance if it *doesn't* run, and if
you don't want it kicking in on really big tables during the day, a
nightly or weekly scheduled vacuum can probably prevent that.
Two other points -- you can adjust how aggressively autovacuum runs;
if it's having a noticeable impact on concurrent queries, try a
small adjustment to autovacuum cost numbers. Also, if you're not on
8.4 (or higher!) yet, the changes in free space management and
vacuums justify the upgrade all by themselves.
-Kevin