[SPARK-54419][SQL] Avoid expanding expensive alias chains in optimizer#55666
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201573 wants to merge 1 commit intoapache:masterfrom
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[SPARK-54419][SQL] Avoid expanding expensive alias chains in optimizer#55666201573 wants to merge 1 commit intoapache:masterfrom
201573 wants to merge 1 commit intoapache:masterfrom
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What changes were proposed in this pull request?
This PR avoids eagerly expanding expensive projection aliases during predicate pushdown, and prevents
CollapseProjectfrom force-inlining multi-use expensive Python-UDF-containing aliases just to merge adjacent Python UDF projections.It also adds a regression test for the deep
withColumnrewrite pattern reported in SPARK-54419.Why are the changes needed?
The optimizer could blow up on deep iterative
withColumnrewrites when a filter above the projection chain referenced an expensive alias. We were expanding those aliases before deciding whether the predicate could stay above the project, and thenCollapseProjectcould still force-inline the expensive chain while merging Python UDF projections.Does this PR introduce any user-facing change?
No.
How was this patch tested?
Verified locally:
./build/sbt "catalyst/testOnly org.apache.spark.sql.catalyst.optimizer.FilterPushdownSuite org.apache.spark.sql.catalyst.optimizer.CollapseProjectSuite"git diff --check