Re: XID wraparound in 8.4

2009/8/11 Anj Adu <fotographs(at)gmail(dot)com>:
> So..we dont have to check the last XID value per table ?
>
> we have a very high volume data warehouse for which autovacuum is not
> suitable due to performance reasons. Can we track the last XID on a
> per-table basis ?

autovacuum is highly tunable so as to remove the burden of running it
and having it suck up all your IO mid day. Are you saying that no
amount of autovacuum tuning can fix the overhead issues of autovac, or
that you've just decided not to use it on principle?

Assuming you do the load at night, vacuum after load, no updates
during the day, I can totally see just turning off autovacuum, but
sometimes it nice to leave it on set to some very low load (i.e.
autovacuum_vacuum_cost_delay=20ms) so that should you forget about
some table, you won't get caught out by table bloat but also won't
have autovacuum killing IO midday.

Just a thought.

Either way, autovacuum WILL kick in if it has to to fix a wrap around
issue even if it's turned off.