Re: vacuum tx id wraparound issues

On Thursday 25 June 2009 10:08:16 Greg Stark wrote:
> On Thu, Jun 25, 2009 at 4:39 PM, Kevin
>
> Kempter<kevink(at)consistentstate(dot)com> wrote:
> > we're inserting an average of 70-100 rows per second into these tables.
>
> Hm. And every row is a separate transaction? That's still only a few
> hundred rows per second. About 25 million per day. You should have
> about 4 days before it hits
> autovacuum_freeze_max_age-vacuum_freeze_min_age.
>
> Are you using subtransactions heavily (savepoints in sql or exception
> clauses in plpgsql)? That could add a multiplier or two to the number
> of transaction ids used up.
>
> You can raise autovacuum_freeze_max_age to, say, 800 million to get
> four times longer before the autovacuum kicks in. You can also lower
> vacuum_freeze_min_age to maybe 25 million. That will give you about
> 775 million transaction ids, almost 8x what you have now, which will
> hopefully give you about a week before autovacuum tries to freeze the
> table
>
>
>
> --
> greg
> http://mit.edu/~gsstark/resume.pdf

Thanks Greg; I'll give these settings a shot.