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  1. Calcite
  2. CALCITE-3355

Deduce whether CASE and COALESCE may produce NULL values

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      When executing queries like: 
      "SELECT COALESCE(name, 'unknown') as name_out FROM PCOLLECTION"
      (input 'name' is nullable)

      There is a need to know whether the result is nullable or not (in this case - not). During validation stage "COALESCE" is being transformed (via SqlValidatorImpl.performUnconditionalRewrites) into a "CASE" statement, which currently does not determine nullability of a result.

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              • Assignee:
                Chunwei Lei Chunwei Lei
                Reporter:
                kirillkozlov Kirill Kozlov
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