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https://issues.apache.org/jira/browse/SPARK-59597?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated SPARK-59597:
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Labels: pull-request-available (was: )
> CTE predicate pushdown has quadratic planning cost for wide CTEs
> ----------------------------------------------------------------
>
> Key: SPARK-59597
> URL: https://issues.apache.org/jira/browse/SPARK-59597
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 4.2.0
> Reporter: Ben Hollis
> Priority: Minor
> Labels: pull-request-available
>
> `PushdownPredicatesAndPruneColumnsForCTEDef` restores attributes from CTE
> references to CTE definitions by linearly searching the entire attribute
> mapping for every referenced attribute. Planning time therefore grows
> quadratically with CTE width.
> The full rule takes about 100 microseconds for 100 columns, 1.65 milliseconds
> for 500 columns, 6.53 milliseconds for 1,000 columns, and 26.54 milliseconds
> for 2,000 columns. Wide CTEs with multiple references repeat this cost during
> optimizer iterations.
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