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Aman Sinha commented on DRILL-3901: ----------------------------------- I should add that the normal performance tests over TPCH sf100 don't show a regression probably because the number of files is relatively small. The performance test with 100K and more files is a manual test that we started tracking recently since Drill users are having hundreds of thousands of files. > Performance regression with doing Explain of COUNT(*) over 100K files > --------------------------------------------------------------------- > > Key: DRILL-3901 > URL: https://issues.apache.org/jira/browse/DRILL-3901 > Project: Apache Drill > Issue Type: Bug > Affects Versions: 1.1.0 > Reporter: Aman Sinha > Assignee: Mehant Baid > > We are seeing a performance regression when doing an Explain of SELECT > COUNT(*) over 100K files in a flat directory (no subdirectories) on latest > master branch compared to a run that was done on Sept 26. Some initial > details (I will have more later): > {code} > master branch on Sept 26 > No metadata cache: 71.452 secs > With metadata cache: 15.804 secs > Latest master branch > No metadata cache: 110 secs > With metadata cache: 32 secs > {code} > So, both cases show regression. > [~mehant] and I took an initial look at this and it appears we might be doing > the directory expansion twice. > -- This message was sent by Atlassian JIRA (v6.3.4#6332)