Re: Autovacuum and OldestXmin - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Autovacuum and OldestXmin
Date
Msg-id 20071126122310.GD6248@alvh.no-ip.org
Whole thread Raw
In response to Re: Autovacuum and OldestXmin  (Simon Riggs <simon@2ndquadrant.com>)
Responses Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
Re: Replacement Selection  (<mac_man2005@hotmail.it>)
List pgsql-hackers
Simon Riggs wrote:
> On Thu, 2007-11-22 at 21:59 -0500, Christopher Browne wrote:

> > I imagine it might be useful to add it to autovac, too.  I thought it
> > was pretty neat that this could be successfully handled by comparison
> > with a single value (e.g. - eldest xmin), and I expect that using a
> > single quasi-global value should be good enough for autovac.
> 
> I've just looked at that to see if it is that easy; I don't think it is.
> 
> That works for slony currently because we vacuum all of the slony tables
> at once. Autovacuum does individual tables so we'd need to store the
> individual values otherwise we might skip doing a VACUUM when it could
> have done some useful work.

Yeah, that was my conclusion too.

-- 
Alvaro Herrera                  http://www.amazon.com/gp/registry/5ZYLFMCVHXC
Voy a acabar con todos los humanos / con los humanos yo acabaré
voy a acabar con todos / con todos los humanos acabaré (Bender)


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