On 01/12/2012 06:17 PM, Tomas Vondra wrote:
> I've run a series fo pgbench benchmarks with the aim to see the effect
> of moving the WAL logs to a separate drive, and one thing that really
> surprised me is that the archive log level seems to give much better
> performance than minimal log level.
How repeatable is this? If you always run minimal first and then
archive, that might be the actual cause of the difference. In this
situation I would normally run this 12 times, with this sort of pattern:
minimal
minimal
minimal
archive
archive
archive
minimal
minimal
minimal
archive
archive
archive
To make sure the difference wasn't some variation on "gets slower after
each run". pgbench suffers a lot from problems in that class.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
