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  1. WiredTiger
  2. WT-5273

Using the minimum modification timestamp improve the checkpoint algorithm.

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    Details

    • Type: Improvement
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: 4.3 Required
    • Component/s: None
    • Labels:
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      Description

      Checkpoint can probably be made more efficient using the minimum modification timestamp, by using that value to determine if checkpoint is required to visit a page.

      If the minimum modification timestamp is less than the stable timestamp then checkpoint should visit the page, otherwise it shouldn't.

      I believe the relevant check is in bt_sync.c around line 246.

      /*
       * Skip clean pages, but need to make sure maximum transaction ID is always updated.
       */
      if (!__wt_page_is_modified(walk->page)) {
          if (((mod = walk->page->modify) != NULL) && mod->rec_max_txn > btree->rec_max_txn)
              btree->rec_max_txn = mod->rec_max_txn;
          if (mod != NULL && btree->rec_max_timestamp < mod->rec_max_timestamp)
              btree->rec_max_timestamp = mod->rec_max_timestamp;
          continue;
      }
      

       

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              • Assignee:
                backlog-server-storage-engines Backlog - Storage Engines Team
                Reporter:
                luke.pearson Luke Pearson
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                • Created:
                  Updated: