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  1. Core Server
  2. SERVER-62815

ProvidedSortSet in EqLookupNode is not optimal.

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    • Icon: Task Task
    • Resolution: Won't Do
    • Icon: Major - P3 Major - P3
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    • Query Execution

    Description

      EqLookupNode::providedSorts() method return a conservative empty ProvidedSortSet.

      This may be inefficient and if used in translation, may introduce unnecessary sort stage, when underlying plan was already sorted.

      The EqLookupNode may provide sort order identical or similar to child sort order, depending on "joinField".

      If "joinField" is disjoint from the sort order, then EqLookupNode will retain it.

      However, if "joinField" is of of the fields in the underlying sort order, then we can only keep the sort prefix up to, but without "joinField".
       

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            backlog-query-execution Backlog - Query Execution
            anna.wawrzyniak@mongodb.com Anna Wawrzyniak
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