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  1. Core Server
  2. SERVER-20770

Consolidate the two code paths for running find commands in the mongo shell

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Details

    • Improvement
    • Status: Open
    • Major - P3
    • Resolution: Unresolved
    • None
    • None
    • Querying, Shell
    • Query Execution
    • 0

    Description

      The shell uses DBCommandCursor to iterate results returned from the "cursor-generating commands" (find, aggregate, listIndexes, listCollections). The implementation is primarily in Javascript:

      https://github.com/mongodb/mongo/blob/bd76599a88e8062c634eeb6918bb30f868bc6042/src/mongo/shell/query.js#L650-L804

      Rewriting this functionality in C++ would most likely make this code run faster. It would also ensure that the shell does not consume excessive memory, since memory required to buffer each batch of results could be reclaimed after the batch is exhausted. Currently, the Javascript engine's garbage collector may not run frequently enough to reclaim memory in a timely manner, especially for queries returning many megabytes worth of results.

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          is related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-23219 DBCommandCursor doesn't route getMore operations to original server

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

          Task - A task that needs to be done. SERVER-58491 Consolidate the C++ native cursor implementation with the DBCommandCursor-based one in the shell js

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

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-65955 Shell's special query path for exhaust queries or "$cmd" queries trips tassert on negative limit

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

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-68213 Stop generating an OP_QUERY-style query representation in the shell's find implementation

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

          Activity

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              backlog-query-execution Backlog - Query Execution
              david.storch@mongodb.com David Storch
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              Dates

                Created:
                Updated: