"Daniel John Debrunner (JIRA)" <[EMAIL PROTECTED]> writes: > Daniel John Debrunner commented on DERBY-2118: > ---------------------------------------------- > > The tests pass for the clearLimit() changes and I performance > changes for the select test ranging from -0.70% to +2.44%. > Sometimes I seem to have trouble getting consistent numbers out of > the test from DERBY-1961, even with an idle machine.
I am also seeing huge variations with the test from DERBY-1961. In fact, I always see huge variations when I'm running performance tests on Derby. My best guess so far is that the native code produced by the hotspot compiler varies between runs (it uses statistics to decide what to optimize and how to optimize it, so it might not be 100% predictable). To eliminate the variation, I usually look at the average of multiple runs. -- Knut Anders
