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Hive QA commented on HIVE-4002: ------------------------------- {color:green}Overall{color}: +1 all checks pass Here are the results of testing the latest attachment: https://issues.apache.org/jira/secure/attachment/12600993/HIVE-4002.patch {color:green}SUCCESS:{color} +1 2903 tests passed Test results: https://builds.apache.org/job/PreCommit-HIVE-Build/588/testReport Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/588/console Messages: {noformat} Executing org.apache.hive.ptest.execution.PrepPhase Executing org.apache.hive.ptest.execution.ExecutionPhase Executing org.apache.hive.ptest.execution.ReportingPhase {noformat} This message is automatically generated. > Fetch task aggregation for simple group by query > ------------------------------------------------ > > Key: HIVE-4002 > URL: https://issues.apache.org/jira/browse/HIVE-4002 > Project: Hive > Issue Type: Improvement > Components: Query Processor > Reporter: Navis > Assignee: Navis > Priority: Minor > Attachments: HIVE-4002.D8739.1.patch, HIVE-4002.D8739.2.patch, > HIVE-4002.D8739.3.patch, HIVE-4002.D8739.4.patch, HIVE-4002.patch > > > Aggregation queries with no group-by clause (for example, select count(*) > from src) executes final aggregation in single reduce task. But it's too > small even for single reducer because the most of UDAF generates just single > row for map aggregation. If final fetch task can aggregate outputs from map > tasks, shuffling time can be removed. > This optimization transforms operator tree something like, > TS-FIL-SEL-GBY1-RS-GBY2-SEL-FS + FETCH-TASK > into > TS-FIL-SEL-GBY1-FS + FETCH-TASK(GBY2-SEL-LS) > With the patch, time taken for auto_join_filters.q test reduced to 6 min (10 > min, before). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira