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. -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---------------------------(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
