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  1. Core Server
  2. SERVER-68323

Decompress BSONColumn one control block at a time

    • Type: Icon: Improvement Improvement
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: None
    • Storage Execution
    • Fully Compatible

      By decompressing one control block at a time in BSONColumn we can reduce the amount of state required in the BSONColumn::Iterator and perform the Simple8b unpacking in a tight(er) loop. This should improve the cache locality and be a performance improvement for the regular case.

      Decompressing objects will be a little more complex as we will need to keep track of decompressed BSONElement per sub-stream and cannot build the returned BSONObj inplace.

      But this tradeoff is most likely acceptable as we should optimize for the most common cases. This can also be a stepping stone towards partial Object decompression where queries are only interested in a subset of the streams.

            Assignee:
            backlog-server-execution [DO NOT USE] Backlog - Storage Execution Team
            Reporter:
            henrik.edin@mongodb.com Henrik Edin
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