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  1. Core Server
  2. SERVER-56520

Time-series inserts spent a lot of time in wt_calc_modify but don't generate deltas

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 5.1.0, 5.0.0-rc2
    • Component/s: None
    • Labels:
      None
    • Backwards Compatibility:
      Fully Compatible
    • Operating System:
      ALL
    • Backport Requested:
      v5.0
    • Steps To Reproduce:
      Hide

      Run TSBS with cpu-only workload. Run db.point_data.stats() and look at the number of cursor modify operations. It doesn't increase during the work load, but attaching a profiles shows significant time spent in wiredtiger_calc_modify.

      Show
      Run TSBS with cpu-only workload. Run db.point_data.stats() and look at the number of cursor modify operations. It doesn't increase during the work load, but attaching a profiles shows significant time spent in wiredtiger_calc_modify .
    • Sprint:
      Execution Team 2021-05-31, Execution Team 2021-06-14

      Description

      We spend 25% of time on attempting to compute WT_MODIFY deltas, but never succeed to the limit of 16 changes. We should either support deltas with more than 16 changes, or find a way to avoid useless calculations.

      Probably it is best to directly change the doc_diff updates into deltas.

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              Assignee:
              yuhong.zhang Yuhong Zhang
              Reporter:
              geert.bosch Geert Bosch
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                Updated:
                Resolved: