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  1. Core Server
  2. SERVER-4437

aggregation: support windowing operation on pipelines

    • Type: Icon: New Feature New Feature
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: Aggregation Framework
    • None
    • Query Optimization

      postgres supports a windowing capability that allows for calculations within a window of visible data; this is for streaming data.

      It's easy to imagine supporting something like a $window pipeline operator, which specifies how many documents to include in the window. Within, aggregate expressions can reference documents within the window using some kind of indexing. This can be used to calculate things like moving averages, e.g., have a window of 5 items, and create a computed field that is (doc[0] + doc[-1] + doc[-2] + doc[-3] + doc[-4])/5, or something like that.

            Assignee:
            backlog-query-optimization [DO NOT USE] Backlog - Query Optimization
            Reporter:
            dan@mongodb.com Daniel Pasette (Inactive)
            Votes:
            10 Vote for this issue
            Watchers:
            11 Start watching this issue

              Created:
              Updated:
              Resolved: