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https://issues.apache.org/jira/browse/HIVE-17626?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Zoltan Haindrich updated HIVE-17626:
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    Attachment:     (was: HIVE-17626.11.patch)

> Query reoptimization using cached runtime statistics
> ----------------------------------------------------
>
>                 Key: HIVE-17626
>                 URL: https://issues.apache.org/jira/browse/HIVE-17626
>             Project: Hive
>          Issue Type: New Feature
>          Components: Logical Optimizer
>    Affects Versions: 3.0.0
>            Reporter: Prasanth Jayachandran
>            Assignee: Zoltan Haindrich
>            Priority: Major
>         Attachments: HIVE-17626.01.patch, HIVE-17626.01wip01.patch, 
> HIVE-17626.02.patch, HIVE-17626.03.patch, HIVE-17626.04.patch, 
> HIVE-17626.05.patch, HIVE-17626.06.patch, HIVE-17626.07A.patch, 
> HIVE-17626.07B.patch, HIVE-17626.08.patch, HIVE-17626.09.patch, 
> HIVE-17626.10.patch, HIVE-17626.11.patch, runtimestats.patch
>
>
> Something similar to "EXPLAIN ANALYZE" where we annotate explain plan with 
> actual and estimated statistics. The runtime stats can be cached at query 
> level and subsequent execution of the same query can make use of the cached 
> statistics from the previous run for better optimization. 
> Some use cases,
> 1) re-planning join query (mapjoin failures can be converted to shuffle joins)
> 2) better statistics for table scan operator if dynamic partition pruning is 
> involved
> 3) Better estimates for bloom filter initialization (setting expected entries 
> during merge)
> This can extended to support wider queries by caching fragments of operator 
> plans scanning same table(s) or matching some operator sequences.



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