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Phabricator commented on HIVE-3562: ----------------------------------- njain has commented on the revision "HIVE-3562 [jira] Some limit can be pushed down to map stage". Sorry, my earlier comments were assuming that the threshold is for number of rows INLINE COMMENTS common/src/java/org/apache/hadoop/hive/conf/HiveConf.java:483 Coming to a earlier comment from Sivaramakrishnan Narayanan, would it be simpler if this was the number of rows ? ql/src/java/org/apache/hadoop/hive/ql/exec/ReduceSinkOperator.java:414 Define 40 as a constant somewhere REVISION DETAIL https://reviews.facebook.net/D5967 To: JIRA, tarball, navis Cc: njain > Some limit can be pushed down to map stage > ------------------------------------------ > > Key: HIVE-3562 > URL: https://issues.apache.org/jira/browse/HIVE-3562 > Project: Hive > Issue Type: Bug > Reporter: Navis > Assignee: Navis > Priority: Trivial > Attachments: HIVE-3562.D5967.1.patch, HIVE-3562.D5967.2.patch, > HIVE-3562.D5967.3.patch > > > Queries with limit clause (with reasonable number), for example > {noformat} > select * from src order by key limit 10; > {noformat} > makes operator tree, > TS-SEL-RS-EXT-LIMIT-FS > But LIMIT can be partially calculated in RS, reducing size of shuffling. > TS-SEL-RS(TOP-N)-EXT-LIMIT-FS -- 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