Re: Performance Tuning Document?

On Thu, 28 Mar 2002, Riebs, Andy wrote:

> > Under the "crossSectionTests(Mixed IR)" part of an OSDB run, a
> > large number of shared_buffers causes severe slowdown on one of
> > the tests -- it goes from a little over 200 seconds to nearly
> > 2000.  I suspect internal lock contention, or maybe it's just
> > that the read() path in Linux is quicker than PG's own cache?
>
> Matthew, are you using the --postgresql=no_hash_index option for OSDB?
> It's conceivable that you are hitting an artifact of the hash index
> problem here.

Ah, that would make a lot of sense.  I'll do a run again with
that option and see what turns up.

Thanks,
Matthew.