Re: Postgres memory usage

On Sep 16, 2004, at 11:26 AM, ruben wrote:

> Thanks Jeff:
>
> This is the output of free:
>
>           total      used     free shared buffers cached
> Mem:     1031012  1018608    12404      0   64984 848160
> -/+ buffers/cache: 105464   925548
> Swap:    2040244        0  2040244
>
a vast majority of your ram is all in cache.
thats is good. It means the memory isn't being wasted.

> shared_buffers and sort_mem are both commented in postgresql.conf:
>
> -bash-2.05b$ grep shared_buf data/postgresql.conf
> #shared_buffers = 64        # 2*max_connections, min 16
> -bash-2.05b$ grep sort_m data/postgresql.conf
> #sort_mem = 512             # min 32
>

that is an extremely small value of shared buffers.
you should set it to at least 1000, maybe even 10000.
You'll likely get a nice performance boost by increasing it.

> I have verified that postgres is not the responsible for the low
> performance of the system, but I just wanted to be sure that memory
> usage is reasonable in a postgres installation.
>
Yes. It is fine, except I'd increase shared_buffers

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