ORCA: keep HAVING above a scalar GbAgg in CNormalizer::FPushable#1693
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yjhjstz wants to merge 1 commit intoapache:mainfrom
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ORCA: keep HAVING above a scalar GbAgg in CNormalizer::FPushable#1693yjhjstz wants to merge 1 commit intoapache:mainfrom
yjhjstz wants to merge 1 commit intoapache:mainfrom
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A scalar (plain) aggregate with no grouping columns always emits exactly one row regardless of input cardinality. Predicates above it (from a HAVING clause) filter that output row, so they cannot be moved onto the aggregate's input without changing semantics: SELECT count(*) FROM t HAVING false -- 0 rows SELECT count(*) FROM t WHERE false -- 1 row (count=0) CNormalizer::FPushable previously only blocked pushing volatile predicates below a GbAgg. Any other predicate -- including a constant false -- was considered pushable because its used-column set was trivially contained in the aggregate's output columns. The normalizer then routed the Select's predicate through the GbAgg and down into its logical child, dropping HAVING semantics for scalar aggregates.
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A scalar (plain) aggregate with no grouping columns always emits exactly one row regardless of input cardinality. Predicates above it (from a HAVING clause) filter that output row, so they cannot be moved onto the aggregate's input without changing semantics:
SELECT count() FROM t HAVING false -- 0 rows
SELECT count() FROM t WHERE false -- 1 row (count=0)
CNormalizer::FPushable previously only blocked pushing volatile predicates below a GbAgg. Any other predicate -- including a constant false -- was considered pushable because its used-column set was trivially contained in the aggregate's output columns. The normalizer then routed the Select's predicate through the GbAgg and down into its logical child, dropping HAVING semantics for scalar aggregates.
Fixes #ISSUE_Number
What does this PR do?
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Breaking Changes
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make installcheckmake -C src/test installcheck-cbdb-parallelImpact
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