On Thu, May 26, 2011 at 10:10 AM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote: > Merlin Moncure <mmoncure@xxxxxxxxx> wrote: > >> So, the challenge is this: I'd like to see repeatable test cases >> that demonstrate regular performance gains > 20%. Double bonus >> points for cases that show gains > 50%. > > Are you talking throughput, maximum latency, or some other metric? I am talking about *any* metric..you've got something, let's see it. But it's got to be verifiable, so no points scored. See my note above about symptoms -- if your symptom of note happens to be unpredictable spikes in fast query times under load, then I'd like to scribble that advice directly into the docs along with (hopefully) some reasoning of exactly why more database managed buffers are helping. As noted, I'm particularly interested in things we can test outside of production environments, since I'm pretty skeptical the Wisconsin Court System is going to allow the internet to log in and repeat and verify test methodologies. Point being: cranking buffers may have been the bee's knees with, say, the 8.2 buffer manager, but present and future improvements may have render that change moot or even counter productive. I doubt it's really changed much, but we really need to do better on this -- all else being equal, the lowest shared_buffers setting possible without sacrificing performance is best because it releases more memory to the o/s to be used for other things -- so "everthing's bigger in Texas" type approaches to postgresql.conf manipulation (not that I see that here of course) are not necessarily better :-). merlin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
