orca: fallback to Postgres optimizer on cross-slice replicated CTE Co…#381
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leborchuk merged 1 commit intoOPENGPDB_6_28_STABLEfrom May 7, 2026
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…nsumer (#375) Inspired by greengage 51fe92e: before Expr->DXL translation, walk the physical tree and track which slice each CTE Producer and Consumer lives on. If a Consumer is on a different slice than its Producer and the Producer's distribution is replicated, force a fallback to the Postgres optimizer. The replicated filter is essential: ordinary cross-slice CTE plans (non-replicated Producer with Gather/Redistribute Consumer) are a normal ORCA pattern and must not trigger fallback. 51fe92e doesn't trigger when a CTE over a replicated table is referenced from a scalar subquery, so the query hangs. This commit replaces the single-point check with a whole-tree walker that catches both cases. Tests: bring the original qp_orca_fallback case from 51fe92e and add a scalar-subquery reproducer in shared_scan guarded by statement_timeout. cherry-pick from 3a9aebf
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orca: fallback to Postgres optimizer on cross-slice replicated CTE Consumer
cherry-pick from 3a9aebf