On Sat, 2006-09-23 at 17:14 -0700, Joshua D. Drake wrote:
> >> Thank you: the problem was the effective_cache_size (which I hadn't
> >> changed from the default of 1000). This machine doesn't have loads of
> >> RAM, but I knocked it up to 65536 and now the query uses the index,
> >> without having to change the statistics.
> >
> > Considering recent discussion about how 8.2 is probably noticeably more
> > sensitive to effective_cache_size than prior releases, I wonder whether
> > it's not time to adopt a larger default value for that setting. The
> > current default of 1000 pages (8Mb) seems really pretty silly for modern
> > machines; we could certainly set it to 10 times that without problems,
> > and maybe much more. Thoughts?
>
> I think that 128 megs is probably a reasonable starting point. I know
> plenty of people that run postgresql on 512 megs of ram. If you take
> into account shared buffers and work mem, that seems like a reasonable
> starting point.
>
I agree, Adopting a higher effective_cache_size seems to be a good thing
to do.
(hmmm.... I must be dreaming again.... But I cannot stop wondering how
it would be to have a smart "agent" that configures these values by
analyzing the machine power and statistical values gathered from
database usage......)