Uploaded image for project: 'Core Server'
  1. Core Server
  2. SERVER-4437

aggregation: support windowing operation on pipelines

    XMLWordPrintableJSON

Details

    • New Feature
    • Status: Closed
    • Major - P3
    • Resolution: Done
    • None
    • None
    • Aggregation Framework
    • None
    • Query Optimization

    Description

      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.

      Attachments

        Issue Links

          Activity

            People

              backlog-query-optimization Backlog - Query Optimization
              dan@mongodb.com Daniel Pasette (Inactive)
              Votes:
              10 Vote for this issue
              Watchers:
              11 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: