On Mon, Oct 01, 2007 at 01:34:32PM -0400, Bill Moran wrote: > This sounds like a caching issue. My guess at what's happening is that > other operations are pushing this data out of the shared_buffers, so > when you run it, the system has to pull a bunch of tuples off the disk > to check them. If you run it again immediately, the tuples are still in > memory, and it runs very fast. You should check your ratio of system cache to shared_buffers. Pushing things out of shared buffers isn't bad if you've got a much bigger OS behind it. The cost of pulling something out of the OS cache is negligable compared to really going to disk. Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.
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