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https://issues.apache.org/jira/browse/HIVE-21857?focusedWorklogId=259168&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-259168
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ASF GitHub Bot logged work on HIVE-21857:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 12/Jun/19 23:27
Start Date: 12/Jun/19 23:27
Worklog Time Spent: 10m
Work Description: jcamachor commented on pull request #671: HIVE-21857
URL: https://github.com/apache/hive/pull/671
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Worklog Id: (was: 259168)
Time Spent: 10m
Remaining Estimate: 0h
> Sort conditions in a filter predicate to accelerate query processing
> --------------------------------------------------------------------
>
> Key: HIVE-21857
> URL: https://issues.apache.org/jira/browse/HIVE-21857
> Project: Hive
> Issue Type: Bug
> Components: CBO
> Reporter: Jesus Camacho Rodriguez
> Assignee: Jesus Camacho Rodriguez
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-21857.01.patch, HIVE-21857.02.patch,
> HIVE-21857.03.patch
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Following approach similar to
> http://db.cs.berkeley.edu/jmh/miscpapers/sigmod93.pdf .
> To reorder predicates in AND conditions, we could rank each of elements in
> the clauses in increasing order based on following formula:
> {code}
> rank = (selectivity - 1) / cost per tuple
> {code}
> Similarly, for OR conditions:
> {code}
> rank = (-selectivity) / cost per tuple
> {code}
> Selectivity can be computed with FilterSelectivityEstimator. For cost per
> tuple, we will need to come up with some heuristic based on how expensive is
> the evaluation of the functions contained in that predicate. Custom UDFs
> could be annotated.
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