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  1. Core Server
  2. SERVER-2094

distinct cheat with indexes

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Details

    • Improvement
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • None
    • 2.5.5
    • Performance
    • None

    Description

      Right now distinct will pull data out of indexes, but will scan the entire thing.
      Can skip whole regions where the key is the same

      Correct way to implement is probably adding a method to a btree bucket like

      getDisinctKeys( int keyOffset )

      Attachments

        Issue Links

          depends on

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-1673 Allow distinct to use indexes

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

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-11939 Implement advanceToNextUniqueKey access method on btree

          • Major - P3 - Major loss of function.
          • Closed
          is duplicated by

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-29244 CLONE - distinct cheat with indexes

          • Major - P3 - Major loss of function.
          • Closed
          is related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-13271 remove surplus projection from distinct

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

          Bug - A problem which impairs or prevents the functions of the product. SERVER-12297 Distinct - nscanned for $in and $or greater than nscannedObjects

          • Minor - P4 - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-9507 Optimize $sort+$group+$first pipeline to avoid full index scan

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

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              Dates

                Created:
                Updated:
                Resolved: