[ https://issues.apache.org/jira/browse/HIVE-3952?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Namit Jain updated HIVE-3952: ----------------------------- Status: Open (was: Patch Available) minor comments > merge map-job followed by map-reduce job > ---------------------------------------- > > Key: HIVE-3952 > URL: https://issues.apache.org/jira/browse/HIVE-3952 > Project: Hive > Issue Type: Improvement > Components: Query Processor > Reporter: Namit Jain > Assignee: Vinod Kumar Vavilapalli > Attachments: HIVE-3952-20130226.txt, HIVE-3952-20130227.1.txt, > HIVE-3952-20130301.txt > > > Consider the query like: > select count(*) FROM > ( select idOne, idTwo, value FROM > bigTable > JOIN > > smallTableOne on (bigTable.idOne = smallTableOne.idOne) > > ) firstjoin > > JOIN > > smallTableTwo on (firstjoin.idTwo = smallTableTwo.idTwo); > where smallTableOne and smallTableTwo are smaller than > hive.auto.convert.join.noconditionaltask.size and > hive.auto.convert.join.noconditionaltask is set to true. > The joins are collapsed into mapjoins, and it leads to a map-only job > (for the map-joins) followed by a map-reduce job (for the group by). > Ideally, the map-only job should be merged with the following map-reduce job. -- 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