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ASF subversion and git services commented on IMPALA-7426: --------------------------------------------------------- Commit cb26d8d82880e934aae9ef211ca7752de510e84a in impala's branch refs/heads/master from [~jbapple] [ https://git-wip-us.apache.org/repos/asf?p=impala.git;h=cb26d8d ] IMPALA-7426: Use Mann-Whitney U to compare benchmarks The Mann-Whitney test can be used to compare samples taken from non-normal distributions, and so can more accurately reflect performance changes than a T-test. This patch does not remove t-tests from the benchmark reporting, it just supplements them by including the Mann-Whitney test result as well. Change-Id: I8d6631ebeba1422b832def5cd68537624f672fa0 Reviewed-on: http://gerrit.cloudera.org:8080/11194 Reviewed-by: Jim Apple <jbapple-imp...@apache.org> Tested-by: Impala Public Jenkins <impala-public-jenk...@cloudera.com> > T-test is an unreliable method for comparing non-normal distributions > --------------------------------------------------------------------- > > Key: IMPALA-7426 > URL: https://issues.apache.org/jira/browse/IMPALA-7426 > Project: IMPALA > Issue Type: Bug > Components: Infrastructure > Reporter: Jim Apple > Assignee: Jim Apple > Priority: Major > > https://en.wikipedia.org/wiki/Student%27s_t-test is for normally distributed > variables, and many Impala benchmarks won't be formally distributed. In > particular, none of them will have negative run times. > We should consider https://en.wikipedia.org/wiki/Nonparametric_statistics > like > https://en.wikipedia.org/wiki/Mann%E2%80%93Whitney_U_test#Comparison_to_Student's_t-test > in report_benchmark_results.py. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org