Consider changing all variadic expressions to short-circuit in SBE

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    • Type: Question
    • Resolution: Unresolved
    • Priority: Major - P3
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    • Affects Version/s: None
    • Component/s: Query Execution
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    • Query Execution
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    • 3
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      As part of SERVER-59785, we have decided to err on the side of consistency and make $concatArrays not short-circuit in SBE, to match the behavior of the rest of the variadic expressions. However, for expressions that take an arbitrary number of arguments, there is a practical performance benefit to short-circuiting early when it is known that the result should be e.g. null.

      This ticket is to consider implementing a uniform policy in SBE, wherein fixed, low-arity expressions always evaluate all arguments, but variadic expressions will attempt to short-circuit when possible for the sake of efficiency.

      The list of variadic expressions currently implemented in SBE are

      • $concat
      • $add
      • $multiply

            Assignee:
            [DO NOT USE] Backlog - Query Execution
            Reporter:
            Kyle Suarez (Inactive)
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              Created:
              Updated: