Re: Now I am back, next thing. Final PGS tuning.

Well, no.. I don't know that. But in a worst case scenario, where everything
is using max, there won't be 3.5 GB for the OS. But for the OS + Postgre
(combined) there will be 2.5 + 2.75 .. But it seems that there is no
greater danger in the effective cache, but a good setting would be nice :)
Is the effective cache only the one for the OS ? not for them combined ?

Sincerely / Jen

On Wed, Apr 8, 2009 at 7:44 PM, David Wilson <david(dot)t(dot)wilson(at)gmail(dot)com>wrote:

> On Wed, Apr 8, 2009 at 12:24 PM, Jennifer Trey <jennifer(dot)trey(at)gmail(dot)com>
> wrote:
>
> > I think I might have misunderstood the effective cache size. Its measured
> in
> > 8kB blocks. So the old number 449697 equals 3.5 GB, which is quite much.
> > Should I lower this? I had plans to use 2.75GB max. Can I put 2.75GB
> there?
> > Should I leave it?
>
> The effective cache size setting is merely letting postgres know how
> much caching it can expect the OS to be doing. If you know that the OS
> isn't going to have more than 2.75 GB available for caching DB files,
> then by all means reduce it. The setting by itself doesn't affect
> postgres memory usage at all, though.
>
> --
> - David T. Wilson
> david(dot)t(dot)wilson(at)gmail(dot)com
>