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https://issues.apache.org/jira/browse/CALCITE-7023?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated CALCITE-7023:
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Labels: pull-request-available (was: )
> Create an optimization pass which can decorrelate subplans
> ----------------------------------------------------------
>
> Key: CALCITE-7023
> URL: https://issues.apache.org/jira/browse/CALCITE-7023
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Affects Versions: 1.39.0
> Reporter: Mihai Budiu
> Assignee: Mihai Budiu
> Priority: Minor
> Labels: pull-request-available
>
> Today the Calcite decorrelator attempts to decorrelate an entire query tree;
> if it fails, it returns the tree unchanged. However, sometimes a query tree
> can contain multiple subtrees rooted by Correlate nodes, some of which can be
> decorrelated using the existing decorrelator.
> One can write an optimization rule which can attempt to apply the
> decorrelator to subtrees rooted at Correlate nodes which do not have any
> Correlate children.
> This "incremental" decorrelation strategy may manage to decorrelate queries
> that otherwise would fail.
> The naive approach would strip the subtree before invoking the decorrelator.
> Maybe there is a better way to do this, but using the decorrelator as a black
> box is easy.
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