Re: analyzing postgresql performance for dbt-2

On Tue, Oct 21, 2003 at 08:35:56PM -0400, Bruce Momjian wrote:
> markw(at)osdl(dot)org wrote:
> > I'm running our DBT-2 workload against PostgreSQL 7.3.4 and I'm having
> > some trouble figuring out what I should be looking for when I'm trying
> > to tune the database. I have results for a decent baseline, but when I
> > try to increase the load on the database, the performance drops.
> > Nothing in the graphs (in the links listed later) sticks out to me so
> > I'm wondering if there are other database statitics I should try to
> > collect. Any suggestions would be great and let me know if I can answer
> > any other questions.
> >
> > Here are a pair of results where I just raise the load on the
> > database, where increasing the load increases the area of the database
> > touched in addition to increasing the transaction rate. The overall
> > metric increases somewhat, but the response time for most of the
> > interactions also increases significantly:
> >
> > http://developer.osdl.org/markw/dbt2-pgsql/158/ [baseline]
> > - load of 100 warehouses
> > - metric 1249.65
> >
> > http://developer.osdl.org/markw/dbt2-pgsql/149/
> > - load of 140 warehouses
> > - metric 1323.90
>
> I looked at these charts and they looked normal to me. It looked like
> your the load increased until your computer was saturated. Is there
> something I am missing?

I've run some i/o tests so I'm pretty sure I haven't saturated that. And it
looks like I have almost 10% more processor time left. I do agree that it
appears something might be saturated, I just don't know where to look...

Thanks,
Mark