AJ Weber wrote:
> Is it possible that some spikes in IO could be attributable to
> the autovacuum process? Is there a way to check this theory?
Taking a look at the ps aux listing, pg_stat_activity, and pg_locks
should help establish a cause, or at least rule out a number of
possibilities. There is a known issue with autovacuum when it tries
to reduce the size of a table which is found to be larger than it
currently needs to be while other transactions try to access the
table. This issue will be fixed in the next minor release for 9.0
and above. If this is the issue a manual VACUUM ANALYZE will fix
things -- at least for a while.
-Kevin