Re: Idea about better configuration options for sort - Mailing list pgsql-hackers

From Jeff
Subject Re: Idea about better configuration options for sort
Date
Msg-id 20040202092910.061af8e3.threshar@torgo.978.org
Whole thread Raw
In response to Re: Idea about better configuration options for sort memory  ("Marc G. Fournier" <scrappy@postgresql.org>)
Responses Re: Idea about better configuration options for sort memory  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
> On Sat, 31 Jan 2004, Tom Lane wrote:
> 
> > "Marc G. Fournier" <scrappy@postgresql.org> writes:
> > > On Sat, 31 Jan 2004, Tom Lane wrote:
> > >> So, what I'd like to do is make btree index creation pay
> > >attention to> vacuum_mem instead of sort_mem, and rename the
> > >vacuum_mem parameter to> some more-generic name indicating that
> > >it's used for more than just> VACUUM.  Any objections so far?
> >
> > > Why not create a seperate index_mem variable instead?  index
> > > creation tends to be, I think, less frequent then vacuum, so
> > > having a higher value for index_mem then vacuum_mem may make sense
> > > ...
> >
> > Well, maybe.  What's in the back of my mind is that we may come
> > across other cases besides CREATE INDEX and VACUUM that should use a
> > "one-off" setting.  I think it'd make more sense to have one
> > parameter than keep on inventing new ones.  For comparison, SortMem
> > is used for quite a few different purposes, but I can't recall
> > anyone needing to tweak an individual one of those purposes other
> > than CREATE INDEX.
> 

I don't know if this would apply here - but foriegn key creation also
benefits hugely from jacking up sort_mem and you also don't do too many
of those in parellel.   

I'm guessing it would be quite in-elegant and kludgy to make that code
use the bigger pool.. it would benefit restore times though.

-- 
Jeff Trout <jeff@jefftrout.com>
http://www.jefftrout.com/
http://www.stuarthamm.net/


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