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Hive QA commented on HIVE-4952: ------------------------------- {color:green}Overall{color}: +1 all checks pass Here are the results of testing the latest attachment: https://issues.apache.org/jira/secure/attachment/12595206/HIVE-4952.D11889.2.patch {color:green}SUCCESS:{color} +1 2749 tests passed Test results: https://builds.apache.org/job/PreCommit-HIVE-Build/259/testReport Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/259/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. > When hive.join.emit.interval is small, queries optimized by Correlation > Optimizer may generate wrong results > ------------------------------------------------------------------------------------------------------------ > > Key: HIVE-4952 > URL: https://issues.apache.org/jira/browse/HIVE-4952 > Project: Hive > Issue Type: Bug > Affects Versions: 0.12.0 > Reporter: Yin Huai > Assignee: Yin Huai > Attachments: HIVE-4952.D11889.1.patch, HIVE-4952.D11889.2.patch, > replay.txt > > > If we have a query like this ... > {code:sql} > SELECT xx.key, xx.cnt, yy.key > FROM > (SELECT x.key as key, count(1) as cnt FROM src1 x JOIN src1 y ON (x.key = > y.key) group by x.key) xx > JOIN src yy > ON xx.key=yy.key; > {\code} > After Correlation Optimizer, the operator tree in the reducer will be > {code} > JOIN2 > | > | > MUX > / \ > / \ > GBY | > | | > JOIN1 | > \ / > \ / > DEMUX > {\code} > For JOIN2, the right table will arrive at this operator first. If > hive.join.emit.interval is small, e.g. 1, JOIN2 will output the results even > it has not got any row from the left table. The logic related > hive.join.emit.interval in JoinOperator assumes that inputs will be ordered > by the tag. But, if a query has been optimized by Correlation Optimizer, this > assumption may not hold for those JoinOperators inside the reducer. -- 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