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branch-4.0:[fix](mtmv) Avoid invalid slot cast in MV null-reject compensation (#66613) - #67255
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seawinde wants to merge 1 commit into
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branch-4.0:[fix](mtmv) Avoid invalid slot cast in MV null-reject compensation (#66613)#67255seawinde wants to merge 1 commit into
seawinde wants to merge 1 commit into
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…pache#66613) Related PR: apache#43539, apache#62492, apache#63268 Problem Summary: When an INNER JOIN query is matched against a LEFT OUTER JOIN materialized view, the rewrite must prove that the nullable side is null-rejected. The MV rule shuttles the nullable-side output Slots through the view plan lineage to normalize Project and Alias outputs before selecting an `IS NOT NULL` compensation Slot. **Root cause:** `AbstractMaterializedViewRule.getShuttledRequireNoNullableViewSlots()` assumed that `ExpressionUtils.shuttleExpressionWithLineage()` always returns `Slot` values and unconditionally used `Slot.class::cast`. The API returns general `Expression` values. Expression JOIN keys such as CAST equality can introduce helper projections whose lineage expands to `Cast`, causing a `ClassCastException` during MV rewrite. The unsafe assumption was introduced by apache#43539. PR apache#62492 added INNER JoinEdge null-reject inference, and apache#63268 materialized that evidence as compensation, making this path more readily reachable. **Current limitation:** This is a conservative crash fix, not transparent rewrite support for CAST or arbitrary derived expressions. If no usable Slot remains after lineage expansion, the existing proof checks return invalid and the MV rewrite safely falls back to base tables. The CAST JOIN case covered by the test therefore still does not use the MV. Using an expression's input Slots as compensation evidence is not generally sound because functions and casts can change nullability semantics; supporting such expressions requires an explicit nullability-preserving proof. Fixed an internal `ClassCastException` during materialized view rewrite for expression-based join keys. Unsupported derived-expression lineage now falls back safely.
hello-stephen
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Aug 28, 2026
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Thank you for your contribution to Apache Doris. Please clearly describe your PR:
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seawinde
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Aug 28, 2026
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run buildall |
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pr: #66613
commitId: 7128b3e