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  1. Core Server
  2. SERVER-69219

Always broadcast queries using read concern level "available" to avoid missing unowned documents when filter includes equality on shard key fields

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    • Type: Icon: Improvement Improvement
    • Resolution: Won't Fix
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: Distributed Query Planning
    • Labels:
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    • Query Optimization
    • QE 2023-02-06, QE 2023-02-20, QE 2023-03-06, QE 2023-03-20, QE 2023-04-03

      Read concern level "available" is used to find unowned documents in a sharded cluster. Allowing these queries be targeted to a subset of the shards is counterproductive because it means unowned documents within a particular chunk range cannot be easily searched for.

      One workaround is to do an aggregation pipeline with {$replaceWith: "$$ROOT"} as it'll prevent the shard targeting optimization.

            Assignee:
            nicholas.zolnierz@mongodb.com Nicholas Zolnierz
            Reporter:
            max.hirschhorn@mongodb.com Max Hirschhorn
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              Created:
              Updated:
              Resolved: