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  1. WiredTiger
  2. WT-6513

Update history store configuration to make overflow keys unlikely

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    Details

    • Type: Improvement
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: 5.0 Required
    • Component/s: None
    • Labels:
      None
    • Story Points:
      5

      Description

      Our current History Store create configuration string is:

      "key_format="IuQQ",value_format="QQQu",block_compressor="WT_HS_COMPRESSOR                                     ",leaf_value_max=64MB,prefix_compression=false"
      

      We should update the configuration to make it very unlikely that we'll ever use overflow keys in the history store. Probably by setting leaf_key_max and internal_key_max to the same value as leaf_value_max.

      The default value is 1/10th of a page split size. The default page size is 4KB meaning that the overflow size is about 400 bytes. MongoDB could definitely be triggering that with indexes at the moment.

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            Assignee:
            backlog-server-storage-engines Backlog - Storage Engines Team
            Reporter:
            alexander.gorrod Alexander Gorrod
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              Created:
              Updated: