Estimate aggregate output rows using existing NDV statistics #20926
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buraksenn wants to merge 2 commits intoapache:mainfrom
Open
Estimate aggregate output rows using existing NDV statistics #20926buraksenn wants to merge 2 commits intoapache:mainfrom
buraksenn wants to merge 2 commits intoapache:mainfrom
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Which issue does this PR close?
Part of #20766
Rationale for this change
Grouped aggregations currently estimate output rows as input_rows, ignoring available NDV statistics. Spark's AggregateEstimation and Trino's AggregationStatsRule both use NDV products to tighten this estimate. This PR is highly referenced by both.
What changes are included in this PR?
Are these changes tested?
Yes existing and new tests that cover different scenarios and edge cases
Are there any user-facing changes?
No