On Thursday, January 27, 2011 02:23:48 PM Cédric Villemain wrote:
> 2011/1/27 Andres Freund <andres@anarazel.de>:
> > On Thursday, January 27, 2011 12:24:10 PM Cédric Villemain wrote:
> >> > maintenance_work_mem = 512MB
> >>
> >> 128MB is usualy enough
> >
> > Uhm, I don't want to be picky, but thats not really my experience. Sorts
> > for index creation are highly dependent on a high m_w_m. Quite regularly
> > I find the existing 1GB limit a probleme here...
>
> That is right for index creation, but not for 'pure' maintenance
> stuff. Once the database is running as usual, there is no really point
> to give auto-vacuum or auto-analyze much more (depend on the raid card
> memory too ...)
Even that I cannot agree with, sorry ;-). If you have a database with much
churn a high m_w_m helps to avoid multiple scans during vacuum of the database
because the amount of dead tuples doesn't fit m_w_m.
Andres