On Wed, 27 Jul 2005 13:30:01 -0700 Josh Berkus <josh@agliodbs.com> wrote:
> Folks, > > I ran a wal_buffer test series. It appears that increasing the > wal_buffers is indeed very important for OLTP applications, potentially > resulting in as much as a 15% average increase in transaction processing. > What's interesting is that this is not just true for 8.1, it's true for > 8.0.3 as well. > > More importantly, 8.1 performance is somehow back up to above-8.0 levels. > Something was broken in June that's got fixed (this test series is based > on July 3 CVS) but I don't know what. Clues? > > Test results are here: > http://pgfoundry.org/docman/view.php/1000041/79/wal_buffer_test.pdf > > As always, detailed test results are available from OSDL, just use: > http://khack.osdl.org/stp/# > where # is the test number. The increase could actually be higher than 15% as 1800 notpm is about the max throughput you can have with 150 warehouses with the default thinktimes. The rule of thumb is about 12 * warehouses, for the throughput. Mark ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
