Tom, All: Ok, finally managed though the peristent efforts of Mark Wong to get some tests through. Here are two tests with the CRC and wall buffer checking completely cut out of the code, as Tom suggested:
5-min checkpoint: http://khack.osdl.org/stp/302738/results/0/ http://khack.osdl.org/stp/302706/results/0/ 60-min checkpoint: http://khack.osdl.org/stp/302739/results/0/ (please note that OSDL is having technical difficulties and some links may not work) This is the performance profile I'd expect and want to see, and the frequency for checkpoints doesn't affect the overall performance at all. Contrast it with these: 5-min checkpoint: http://khack.osdl.org/stp/302671/results/0/ I don't hae a 60-minute checkpoint for comparison because of failures on the STP :-( So, now that we know what the performance bottleneck is, how do we fix it? -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq