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https://issues.apache.org/jira/browse/SPARK-13940?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Hyukjin Kwon resolved SPARK-13940.
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Resolution: Incomplete
> Predicate Transitive Closure Transformation
> -------------------------------------------
>
> Key: SPARK-13940
> URL: https://issues.apache.org/jira/browse/SPARK-13940
> Project: Spark
> Issue Type: Improvement
> Components: Optimizer
> Affects Versions: 1.6.0
> Reporter: Alex Antonov
> Priority: Major
> Labels: bulk-closed
>
> A relatively simple transformation is missing from Catalyst's arsenal -
> generation of transitive predicates. For instance, if you have got the
> following query:
> {code}
> select *
> from table1 t1
> join table2 t2
> on t1.a = t2.b
> where t1.a = 42
> {code}
> then it is a fair assumption that t2.b also equals 42 hence an additional
> predicate could be generated. The additional predicate could in turn be
> pushed down through the join and improve performance of the whole query by
> filtering out the data before joining it.
> Such an transformation exists in Oracle DB and called transitive closure
> which hopefully should explain the title of this Jira
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