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Posted to dev@hive.apache.org by "Vineet Garg (JIRA)" <ji...@apache.org> on 2017/08/12 22:47:00 UTC

[jira] [Created] (HIVE-17308) Improvement in join cardinality estimation

Vineet Garg created HIVE-17308:
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             Summary: 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


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.



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