Re: Strange performance issue

On Mon, 26 Nov 2001, Brent Verner wrote:

> On 26 Nov 2001 at 08:04 (-0800), Mike Harding wrote:
> |
> | I am using FreeBSD-4.4-STABLE, cvsup'd last weekend, and the version
> | is 7.1.3 as reflected in the FreeBSD port system.
> |
>
> Testing your case with postgres 7.2b3 on FBSD 4.4-STABLE, I do not
> see what you described. Below is a copy of top(1) running while
> running two instances of your script.

> 9575 pgsql -4 0 6044K 3480K semwai 0:04 0.88% 0.88% postgres

When I first installed postgresql on FreeBSD 4.4-Stable I also noticed it
used considerable CPU even with somewhat trivial tasks. After doing some
reading I found out about increasing buffer, sort_mem and several FreeBSD
memory settings. This seems to have helped. For example the top line above
leads me to believe buffers and sort_mem were twicked on that machine.

My exact settings are:
postgresql.conf
shared_buffers = 5000
sort_mem = 8192

/etc/sysctl.conf
kern.ipc.shmall=65535
kern.ipc.shmmax=67108864
kern.ipc.shm_use_phys=1

The machine in question is stable as of early November and it has 192MB.
Each of the posgresql sessions take about 55MB on my machine and I usually
only have 1 or 2 sessions going (for now).