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  1. Core Server
  2. SERVER-76905

Performance Issue about Clustered Collection : where there are more than one _id search condition, the search would fallback to COLLSCAN

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    • Type: Icon: Bug Bug
    • Resolution: Unresolved
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: 6.0.5
    • Component/s: None
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      1. use MongoDB 6.0.5 Community
      2. create clustered collection
      3. run query explain with { id: {$in: ["1"] }} vs {_id:

      { $in: ["1" ,"2"] }

      }

      Show
      1. use MongoDB 6.0.5 Community 2. create clustered collection 3. run query explain with { id: {$in: ["1"] }} vs {_id: { $in: ["1" ,"2"] } }

      Hi there, I try to use clustered collection. But I found out when I use find method with query {_id: { $in: ["1", "2"] }}

      when there are more than one condition in $in array, the query performance is really bad because it fallback from CLUSTERED_IXSCAN to COLLSCAN

        1. 截圖 2023-05-07 上午10.43.41.png
          截圖 2023-05-07 上午10.43.41.png
          200 kB
        2. 截圖 2023-05-07 上午10.43.55.png
          截圖 2023-05-07 上午10.43.55.png
          212 kB

            Assignee:
            Unassigned Unassigned
            Reporter:
            sj82516@gmail.com 元傑 鄭
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              Created:
              Updated: