Extend the classic $lookup LRU result cache (SERVER-127901) to cover $lookup stages that have absorbed a $unwind

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    • Type: Task
    • Resolution: Unresolved
    • Priority: Minor - P4
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      SERVER-127901 added a per-localField-value LRU result cache to classic $lookup for pure localField/foreignField equijoins (LookupResultCache in lookup_result_cache.h/.cpp). The cache is unconditionally disabled (LookupResultCache::createDisabled()) whenever _hasAbsorbedUnwindSrc is true — see the guard and TODO in LookUpStage's constructor and makeResultCache() in src/mongo/db/exec/agg/lookup_stage.cpp.

            Assignee:
            Unassigned
            Reporter:
            Prabhas Penumatsa
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              Created:
              Updated: