Re: Manual vacs 5x faster than autovacs?

Wayne Beaver <wayne@acedsl.com> writes:
> Running Pg 8.3RC2, Linux server, w/8GB RAM, OpenSuSE 10.2 OS (yes, I
> know that's old). I have seen *really* long-running autovacs eating up
> system resources. While the below is not an example of *really* long,
> it shows how I killed an autovac which had been running for more than
> 10 minutes, then ran a VAC FULL ANALYZE on same exact table in about
> ~2 min. Any wisdom here? Attributable to autovac_worker settings?

autovacuum_vacuum_cost_delay.  Is the slow autovac *really* eating
a noticeable amount of system resources?  I would think that a full
speed manual vacuum would be a lot worse.

            regards, tom lane