Kieran Cooper, Lyris UK wrote:
>> What is it about autovacuum that isn't working for you?
>
> Hi Matthew. I have to admit that I haven't tested full yet, but here's
> the scenario:
> When Lyris sends a mailing there is an intense amount of database
> activity - particularly on two tables. When I had auto vacuum set up,
> the database just wasn't responding fast enough, so the mailing speed
> dropped as Lyris dynamically adjusted based on the speed of db response.
> I guess what I need to do is tweak the intervals and the sleep time so
> that vacuum backs off when the database is really busy - do you have any
> thoughts on what settings I should try in order to acheive that?
The sleep intervals are one thing, but what you probably really want to
play with are they vacuum cost delay and limit settings. This is
throttle down how much IO autovacuum can consume.
http://www.postgresql.org/docs/8.2/interactive/runtime-config-autovacuum.html