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  1. Core Server
  2. SERVER-57547

Add SBE builder for $group accumulators

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Details

    • Task
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • None
    • 5.1.0-rc0
    • None
    • None
    • Fully Compatible
    • Query Execution 2021-07-12, Query Execution 2021-07-26

    Description

      Unlike agg expressions, which are transformed from Expression* to an SBE PlanStage tree, $group accumulators will need to transformed from from an AccumulationStatement (or related type) into two sets of SBE expressions: one set for "accumulation" and another for "finalization."

      For example, $avg will be implemented with two accumulators: one for summing all of the elements and another for counting. The "finalization" expression will divide the sum by the count.

      $push on the other hand will be implemented with just an accumulator, which pushes to an array (there is no need for "finalizing").

       

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          depends on

          Task - A task that needs to be done. SERVER-57899 Make it more convenient to switch on type of AccumulatorStatement

          • Major - P3 - Major loss of function.
          • Closed
          is depended on by

          Task - A task that needs to be done. SERVER-57549 Implement translation of $accumulator to SBE

          • Major - P3 - Major loss of function.
          • Backlog

          Task - A task that needs to be done. SERVER-57550 Implement translation of $addToSet

          • Major - P3 - Major loss of function.
          • Closed

          Task - A task that needs to be done. SERVER-57551 Implement translation of $first, $last, $min, $max accumulators to SBE

          • Major - P3 - Major loss of function.
          • Closed

          Task - A task that needs to be done. SERVER-57552 Implement translation of $stdDevPop and $stdDevSamp accumulators to SBE

          • Major - P3 - Major loss of function.
          • Closed

          Task - A task that needs to be done. SERVER-57553 Implement translation of $sum accumulator to SBE

          • Major - P3 - Major loss of function.
          • Closed

          Task - A task that needs to be done. SERVER-58070 Support accumulator $topN in SBE

          • Major - P3 - Major loss of function.
          • Closed

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              eric.cox@mongodb.com Eric Cox (Inactive)
              ian.boros@mongodb.com Ian Boros
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              Dates

                Created:
                Updated:
                Resolved: