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  1. Core Server
  2. SERVER-97899

Create EstimatorFactory and refactor query planner to use it

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    • Type: Icon: Improvement Improvement
    • Resolution: Unresolved
    • Priority: Icon: Major - P3 Major - P3
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    • Affects Version/s: None
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    • Query Optimization

      After SERVER-97465, QueryPlanner::planWithCostBasedRanker access histograms via QueryPlannerParams -> CollectionInfo -> CollectionStatistics and the sampling estimator via a parameter to planWithCostBasedRanker. Neither of these are ideal locations for these parameters.

      The tasks for this ticket are:

      • Introduce a interface or class EstimatorFactory which has function to construct a HistogramEstimator, SamplingEstimator and HeuristicEstimator (we will add new estimators here in the future). This may require refactoring histogram CE to be a proper class that interacts with the stats catalog rather than have static functions (we can repurpose CollectionStatistics for this purpose).
      • Refactor QueryPlanner methods to take EstimatorFactory as parameter. Remove SamplingEstimator and CollectionStats arguments.

            Assignee:
            Unassigned Unassigned
            Reporter:
            ben.shteinfeld@mongodb.com Ben Shteinfeld
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              Created:
              Updated: