Laszlo Fogas <laszlo(at)falconsocial(dot)com> wrote:
> We have a reoccurring problem of slowness initially in every 2
> months, after enabling autovacuum every 6 months what only full
> vacuum can solve. It's kind of a problem as it requires 2hrs
> downtime and we want to avoid that. What we are doing now is
> moving to Postgres 9.1 as a desperate measure, but we would like
> to understand better the root cause of the problem.
Your autovacuum is not configured to be aggressive enough. The
upgrade should help, as autovacuum has been improved in recent
releases, but you may need to increase autovacuum_max_workers,
decrease autovacuum_naptime, etc. There are a lot of knobs, and I
often find I need to make autovacuum a bit more aggressive than the
defaults to keep things in good shape.
-Kevin