[SPARK-58323][SQL][4.0] Materialize AliasAware output ordering and partitioning to avoid StackOverflowError#57532
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…rtitioning to avoid StackOverflowError ### What changes were proposed in this pull request? Backport of SPARK-58323 (apache#57502) to branch-4.0. `AliasAwareQueryOutputOrdering.outputOrdering` and `BroadcastHashJoinExec`'s output-partitioning expansion build their results with `multiTransform`, which returns a `LazyList`, and store the bounded result unforced. This forces them into strict collections with `.toList`, right after the existing `.take(...)` so the lazy short-circuit during candidate generation is preserved. Tailored for branch-4.0 (differs from the master PR): - The `PartitioningPreservingUnaryExecNode.outputPartitioning` change is omitted: on branch-4.0 that method already materializes a strict collection (`...iterator.flatMap(...).take(...).toSeq` over an `Iterator`), so there is no unforced `LazyList` to fix. - The `BroadcastJoinSuite` single-element assertion change is omitted: on branch-4.0 `expandOutputPartitioning` always returns a `PartitioningCollection` (no `case p :: Nil` unwrap), so the single-element output shape is unchanged. ### Why are the changes needed? Each plan node re-wraps the child ordering/partitioning's unforced `LazyList`, so across a deep projection chain the deferred nesting grows unbounded and overflows the stack when the ordering/partitioning is later serialized or deeply traversed. On master this was observed as a driver `StackOverflowError` at `DAGScheduler.submitMissingTasks` during task serialization of a `SortedMergeCoalescedRDD` (SPARK-55715) on a large bucketed `MERGE`. That RDD and code path do not exist on branch-4.0, so this backport is defensive hardening of the same latent lazy-collection-in-output-ordering/partitioning hazard, which has existed since the `multiTransform` path was introduced in SPARK-42049. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? New test in `ProjectedOrderingAndPartitioningSuite` asserting `sameOrderExpressions` is strict (not a `LazyList`); it fails before this change and passes after. Existing `ProjectedOrderingAndPartitioningSuite` / `BroadcastJoinSuite` / `BroadcastJoinSuiteAE` pass. ### Was this patch authored or co-authored using generative AI tooling? Generated-by: Claude Opus 4.8
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…rtitioning to avoid StackOverflowError ### What changes were proposed in this pull request? Backport of SPARK-58323 (#57502) to branch-4.0. `AliasAwareQueryOutputOrdering.outputOrdering` and `BroadcastHashJoinExec`'s output-partitioning expansion build their results with `multiTransform`, which returns a `LazyList`, and store the bounded result unforced. This forces them into strict collections with `.toList`, right after the existing `.take(...)` so the lazy short-circuit during candidate generation is preserved. Tailored for branch-4.0 (differs from the master PR): - The `PartitioningPreservingUnaryExecNode.outputPartitioning` change is omitted: on branch-4.0 that method already materializes a strict collection (`...iterator.flatMap(...).take(...).toSeq` over an `Iterator`), so there is no unforced `LazyList` to fix. - The `BroadcastJoinSuite` single-element assertion change is omitted: on branch-4.0 `expandOutputPartitioning` always returns a `PartitioningCollection` (no `case p :: Nil` unwrap), so the single-element output shape is unchanged. ### Why are the changes needed? Each plan node re-wraps the child ordering/partitioning's unforced `LazyList`, so across a deep projection chain the deferred nesting grows unbounded and overflows the stack when the ordering/partitioning is later serialized or deeply traversed. On master this was observed as a driver `StackOverflowError` at `DAGScheduler.submitMissingTasks` during task serialization of a `SortedMergeCoalescedRDD` (SPARK-55715) on a large bucketed `MERGE`. That RDD and code path do not exist on branch-4.0, so this backport is defensive hardening of the same latent lazy-collection-in-output-ordering/partitioning hazard, which has existed since the `multiTransform` path was introduced in SPARK-42049. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? New test in `ProjectedOrderingAndPartitioningSuite` asserting `sameOrderExpressions` is strict (not a `LazyList`); it fails before this change and passes after. Existing `ProjectedOrderingAndPartitioningSuite` / `BroadcastJoinSuite` / `BroadcastJoinSuiteAE` pass. ### Was this patch authored or co-authored using generative AI tooling? Generated-by: Claude Opus 4.8 Closes #57532 from peter-toth/SPARK-58323-aliasaware-strict-ordering-partitioning-4.0. Authored-by: Peter Toth <peter.toth@gmail.com> Signed-off-by: Peter Toth <peter.toth@gmail.com>
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Thank you @dongjoon-hyun for the review. |
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What changes were proposed in this pull request?
Backport of SPARK-58323 (#57502) to branch-4.0.
AliasAwareQueryOutputOrdering.outputOrderingandBroadcastHashJoinExec's output-partitioning expansion build their results withmultiTransform, which returns aLazyList, and store the bounded result unforced. This forces them into strict collections with.toList, right after the existing.take(...)so the lazy short-circuit during candidate generation is preserved.Tailored for branch-4.0 (differs from the master PR):
PartitioningPreservingUnaryExecNode.outputPartitioningchange is omitted: on branch-4.0 that method already materializes a strict collection (...iterator.flatMap(...).take(...).toSeqover anIterator), so there is no unforcedLazyListto fix.BroadcastJoinSuitesingle-element assertion change is omitted: on branch-4.0expandOutputPartitioningalways returns aPartitioningCollection(nocase p :: Nilunwrap), so the single-element output shape is unchanged.Why are the changes needed?
Each plan node re-wraps the child ordering/partitioning's unforced
LazyList, so across a deep projection chain the deferred nesting grows unbounded and overflows the stack when the ordering/partitioning is later serialized or deeply traversed. On master this was observed as a driverStackOverflowErroratDAGScheduler.submitMissingTasksduring task serialization of aSortedMergeCoalescedRDD(SPARK-55715) on a large bucketedMERGE. That RDD and code path do not exist on branch-4.0, so this backport is defensive hardening of the same latent lazy-collection-in-output-ordering/partitioning hazard, which has existed since themultiTransformpath was introduced in SPARK-42049.Does this PR introduce any user-facing change?
No.
How was this patch tested?
New test in
ProjectedOrderingAndPartitioningSuiteassertingsameOrderExpressionsis strict (not aLazyList); it fails before this change and passes after. ExistingProjectedOrderingAndPartitioningSuite/BroadcastJoinSuite/BroadcastJoinSuiteAEpass.Was this patch authored or co-authored using generative AI tooling?
Generated-by: Claude Opus 4.8