[ https://issues.apache.org/jira/browse/KUDU-2380?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Todd Lipcon resolved KUDU-2380. ------------------------------- Resolution: Fixed Fix Version/s: 1.8.0 > Selective predicates when selecting high number of columns burns CPU in > SerializeRowBlock > ----------------------------------------------------------------------------------------- > > Key: KUDU-2380 > URL: https://issues.apache.org/jira/browse/KUDU-2380 > Project: Kudu > Issue Type: Improvement > Components: perf, tserver > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Major > Fix For: 1.8.0 > > Attachments: pprof.kudu-tserver.samples.cpu.001.pb.gz > > > Testing a table with 280 columns, I found the following performance > characteristic: > - scanning all 280 columns with a selective non-key predicate which matches 0 > rows took 8.28s > - scanning no columns (count query) with the same predicate which matches 0 > rows took 314ms. > This suggests that we are burning 96% of our CPU doing useless work for this > query. -- This message was sent by Atlassian JIRA (v7.6.3#76005)