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https://issues.apache.org/jira/browse/HIVE-21867?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jesus Camacho Rodriguez updated HIVE-21867:
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Description: The problem was tackled for CBO in HIVE-21857. Semijoin
filters are introduced later in the planning phase. Follow similar approach to
sort them, trying to accelerate filter evaluation. (was: 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.)
> Sort semijoin conditions to accelerate query processing
> -------------------------------------------------------
>
> Key: HIVE-21867
> URL: https://issues.apache.org/jira/browse/HIVE-21867
> Project: Hive
> Issue Type: Bug
> Components: CBO
> Reporter: Jesus Camacho Rodriguez
> Assignee: Jesus Camacho Rodriguez
> Priority: Major
> Labels: pull-request-available
>
> The problem was tackled for CBO in HIVE-21857. Semijoin filters are
> introduced later in the planning phase. Follow similar approach to sort them,
> trying to accelerate filter evaluation.
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