[ https://issues.apache.org/jira/browse/HIVE-17767?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Vineet Garg updated HIVE-17767: ------------------------------- Attachment: HIVE-17767.2.patch > Rewrite correlated EXISTS/IN subqueries into LEFT SEMI JOIN > ----------------------------------------------------------- > > Key: HIVE-17767 > URL: https://issues.apache.org/jira/browse/HIVE-17767 > Project: Hive > Issue Type: Improvement > Components: Query Planning > Reporter: Vineet Garg > Assignee: Vineet Garg > Priority: Major > Attachments: HIVE-17767.1.patch, HIVE-17767.2.patch > > > Currently such queries are written into group by + inner join with value > generator and is inefficient. Value generator consists of join with outer > query to fetch all correlated values. This value generator could be > completely eliminated if such queries are instead rewritten into LEFT SEMI > JOIN. > Note that to do this first hive need to support LEFT SEMI JOIN with non-equi > condition (HIVE-17766). -- This message was sent by Atlassian JIRA (v6.4.14#64029)