From: | Anj Adu <fotographs(at)gmail(dot)com> |
---|---|
To: | Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> |
Cc: | Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Devrim GÜNDÜZ <devrim(at)gunduz(dot)org>, pgsql-admin(at)postgresql(dot)org |
Subject: | Re: XID wraparound in 8.4 |
Date: | 2009-08-12 03:50:43 |
Message-ID: | f2fd819a0908112050oab0128ey1876c61c764690a3@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-admin |
Reason we dont turn on autovacuum is that we are a "high-volume"
insert shop with minimal updates..We have about 200 million inserts
and a few thousand updates only. Most tables are partitions and get
dropped as part of the purge. Hence..autovacuum is a waste of
resources. However...the XID issue will force the need for an
autovacuum at some point..hence we do it as a one-off occasionally.
2009/8/11 Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>:
> 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.
>
From | Date | Subject | |
---|---|---|---|
Next Message | Alvaro Herrera | 2009-08-12 04:56:02 | Re: XID wraparound in 8.4 |
Previous Message | Alvaro Herrera | 2009-08-12 00:28:55 | Re: XID wraparound in 8.4 |