Re: Shared_buffers hint

On Mon, Oct 6, 2008 at 7:56 AM, Rafael Domiciano
<rafael(dot)domiciano(at)gmail(dot)com> wrote:
> I'm using 8.3.3 version in this machine..!
> So, the shared_buffers set to 100Mb is ok? Or 500Mb is better?
> This server we call "Reporter Server", so it's used to do heavy reports for
> a few users only (I could say 5 users).
> What could be the best config for my server with:
> 2 Gb RAM
> 300 GB HD
> Postgres 8.3
> Dual Core

100M is probably adequate. 2G is a pretty small database server
memory wise. I assume by 300G HD you mean a single hard drive. Since
a single hard drive is going to limit the speed at which you can
access data from it, I'd leave shared_buffers at 100M and let the OS
cache data for you. Also, look at work_mem. You might want to set
those few heavy users to have more work_mem than the other users.

alter user heavyuser set work_mem=128000;

note that work_mem is per user sort, so it's quite possible to exhaust
main memory if you set it high for everybody and they all do sorts on
large sets suddenly.