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https://issues.apache.org/jira/browse/HIVE-21857?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jesus Camacho Rodriguez updated HIVE-21857:
-------------------------------------------
Description:
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.
was:
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 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
>
> 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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