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  1. IMPALA
  2. IMPALA-4289

Mark slots produced by NDV() and NDV_NO_FINALIZE() as non-nullable.

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      COMPUTE STATS and COMPUTE INCREMENTAL STATS might get a slight speedup if we marked the aggregation slots as non-nullable.

      Of course, regular uses of NDV() and NDV_NO_FINALIZE() would also benefit.

      Not sure what speedup might be (simple experiments were inconclusive), but making this change seems strictly better than leaving the slots nullable.

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            alex.behm Alexander Behm
            alex.behm Alexander Behm
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