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  1. WiredTiger
  2. WT-4716

Changing log compression settings became more difficult with stable checkpoints.

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    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Minor - P4
    • Resolution: Won't Fix
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
    • Labels:
      None
    • Story Points:
      8
    • Sprint:
      Storage Engines 2019-06-17, Storage Engines 2019-07-01
    • Backport Requested:
      v4.2

      Description

      In 3.6 on a clean shutdown and restart, WT recovery does not need to replay any of its journal.

      However on 4.0+, shutting down with a stable checkpoint will often need to replay log entries as timestamped writes to logged tables won't necessarily be persisted in the checkpoint on close.

      When opening WT with a journal compressor setting, that value is used to interpret existing compressed log records as well as the setting to write out new log records. This makes changing the compression setting for log records difficult. I think for many users, a best effort to try and read existing log records with the known compression libraries would work for most cases. If none of the decompression attempts for a log record succeeded, I suspect failing with the same error then would be acceptable.

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            • Assignee:
              alex.cameron Alex Cameron
              Reporter:
              daniel.gottlieb Daniel Gottlieb
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              Dates

              • Created:
                Updated:
                Resolved: