On Wed, Oct 06, 2004 at 01:27:26PM -0400, Alvaro Herrera wrote: > On Wed, Oct 06, 2004 at 10:01:42AM -0700, Mark Wong wrote: > > On Mon, Oct 04, 2004 at 02:42:43PM -0400, Greg Stark wrote: > > > Mark Wong <[EMAIL PROTECTED]> writes: > > > > > > > Links to results are here: > > > > 7.5devel - http://www.osdl.org/projects/dbt2dev/results/dev4-010/128/ > > > > 8.0beta3 - http://www.osdl.org/projects/dbt2dev/results/dev4-010/180/ > > > > > > Are those cyclic spikes an artifact of the load of the tests? Or are they > > > artifacts of the postgres checkpoint process? > > > > In the past, they have been artifacts of the checkpoint process. They > > do smooth out as I increase the checkpoint segments and the timeout. > > Although I know that doesn't exactly exclude other explanations. > > Another knob to test would be bgwriter parameters, say bgwriter_percent > to maybe 5 or 10. That should distribute more evenly the load. > > http://archives.postgresql.org/pgsql-hackers/2004-09/msg00623.php >
Cool, I increased bgwriter_percent from the default to 10, and that certainly smoothed things out: http://www.osdl.org/projects/dbt2dev/results/dev4-010/182/ The overall throughput didn't really improved though. :( Mark ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org