Hashimoto Yuya <hill_climb(at)hotmail(dot)com> writes:
> [ lots of time spent by stats collector process ]
How large is $PGDATA/global/pgstat.stat ?
If it's very large (many MB), try doing pg_stats_reset(). If that makes
the stats collector CPU usage drop, consider an update to PG 8.4.x,
which is more efficient at dealing with large stats files.
regards, tom lane