Disable decorrelation for count() with no grouping columns #1310
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my-ship-it
reviewed
Aug 18, 2025
| if (0 == popAggOriginal->Pdrgpcr()->Size()) | ||
| { | ||
| CColRef *pcrCount = nullptr; | ||
| if (CUtils::FHasCountAgg((*pexpr)[1], &pcrCount)) |
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It's OK to process count star and count any here. But it's a general problem, namely, any AggFunc with not nulll initval we should process here.
my-ship-it
approved these changes
Aug 18, 2025
my-ship-it
reviewed
Aug 18, 2025
| BOOL fGeneratedByQuantified = popSubquery->FGeneratedByQuantified(); | ||
| if (fGeneratedByQuantified || | ||
| (fHasCountAggMatchingColumn && 0 == pgbAgg->Pdrgpcr()->Size())) | ||
| if (fGeneratedByQuantified) |
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And please add a test case, thanks!
my-ship-it
reviewed
Aug 18, 2025
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| *ppexprResidualScalar = pexprCoalesce; | ||
| } | ||
| // we produce Null if count(*) value is -1, |
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Why we change logic here?
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Fixes #1309
What does this PR do?
Type of Change
Breaking Changes
Test Plan
make installcheckmake -C src/test installcheck-cbdb-parallelImpact
Performance:
User-facing changes:
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