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  1. Core Server
  2. SERVER-73717

When using in-memory storage engine spill to disk doesn't always work

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    • Type: Icon: Bug Bug
    • Resolution: Won't Fix
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: None
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    • Query Execution
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      The Hash Agg stage in the SBE engine spills using a record store as opposed to files as in the classic engine. There is a statistic query execution tracks "spilledDataStorageSize" introduced in https://jira.mongodb.org/browse/SERVER-73311 which reports the bytes spilled to the record store.

      When testing this behavior on an in memory required build variant, the value of spilledDataStorage size is 0, even though spilling is allowed. ([patch build: ). 

      This poses the question:

      Should we even allow spilling to record stores when running on an in memory build?

      If no, we can disable spilling when in memory stores. 

      If yes, we can spill to a file instead of record store, or ignore the memory limit.

            Assignee:
            backlog-query-execution [DO NOT USE] Backlog - Query Execution
            Reporter:
            adi.agrawal@mongodb.com Adi Agrawal
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              Created:
              Updated:
              Resolved: