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  1. IMPALA
  2. IMPALA-4728

materialize expressions for window sorts vs lazy expression evaluation

    Details

    • Type: New Feature
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: Impala 2.8.0
    • Fix Version/s: Impala 2.9.0
    • Component/s: Frontend
    • Labels:

      Description

      Currently Impala uses lazy evaluation for expressions. This can result in a performance overhead when using or reusing expressions in things like a window function order by vs having the expression materialized as a projection from the underlying relation, especially if the expression is used in multiple places.

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              • Assignee:
                twmarshall Thomas Tauber-Marshall
                Reporter:
                grahn Greg Rahn
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                • Created:
                  Updated:
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