Re: First steps with 8.3 and autovacuum launcher

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Alvaro Herrera <alvherre(at)commandprompt(dot)com>
Cc: Simon Riggs <simon(at)2ndquadrant(dot)com>, "Matthew T(dot) O'Connor" <matthew(at)zeut(dot)net>, Heikki Linnakangas <heikki(at)enterprisedb(dot)com>, Gregory Stark <stark(at)enterprisedb(dot)com>, Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>, Guillaume Smet <guillaume(dot)smet(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: First steps with 8.3 and autovacuum launcher
Date: 2007-10-01 23:14:21
Message-ID: 24041.1191280461@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> So you say we should make any job that needs an exclusive lock on a
> table to be able to cancel a running autovac job?

I think we're going to be seeing complaints of this form until we do that.
The only reason this particular discussion is about pg_restore is that
that's the OP's first exposure to 8.3.

> If we did that, autovac couldn't do very much of anything.

In the worst case autovac could be starved out for a long time.
I don't have any immediate good idea about how to fix that, but
the worst consequences could be avoided if we disable the cancellation
ability when running an anti-wraparound vacuum. Further down the road
(*not* 8.3), when we teach autovac about maintenance windows, it might
also disregard cancels during a maintenance window.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2007-10-01 23:25:16 Re: PG on NFS may be just a bad idea
Previous Message Matthew T. O'Connor 2007-10-01 23:04:39 Re: First steps with 8.3 and autovacuum launcher