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Lefty Leverenz commented on HIVE-17308: --------------------------------------- Wow, you're fast! > Improvement in join cardinality estimation > ------------------------------------------ > > Key: HIVE-17308 > URL: https://issues.apache.org/jira/browse/HIVE-17308 > Project: Hive > Issue Type: Improvement > Components: Query Planning > Reporter: Vineet Garg > Assignee: Vineet Garg > Fix For: 3.0.0 > > Attachments: HIVE-17308.1.patch, HIVE-17308.2.patch, > HIVE-17308.3.patch, HIVE-17308.4.patch, HIVE-17308.5.patch, > HIVE-17308.6.patch, HIVE-17308.7.patch, HIVE-17308.8.patch > > > Currently during logical planning join cardinality is estimated assuming no > correlation among join keys (This estimation is done using exponential > backoff). Physical planning on the other hand consider correlation for multi > keys and uses different estimation. We should consider correlation during > logical planning as well. -- This message was sent by Atlassian JIRA (v6.4.14#64029)