> 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
artifactof the hash index problem here.
/andy
---
Andy Riebs, andy.riebs@compaq.com High Performance Technical
(w) 603-884-1521, (fax) 603-884-0630 Computing/Linux Group
<http://cub.sourceforge.net/> Compaq Computer Corporation
(h) ariebs@earthlink.net <http://www.compaq.com/linux>
<http://osdb.sourceforge.net/> <http://opensource.compaq.com>