Uploaded image for project: 'Core Server'
  1. Core Server
  2. SERVER-85024

Histogram-based cardinality estimation for conjunctions

    XMLWordPrintableJSON

Details

    • Icon: Task Task
    • Resolution: Won't Fix
    • Icon: Major - P3 Major - P3
    • None
    • None
    • None
    • Query Optimization

    Description

      There are several options to explore here, and its not clear of the advantages of each:

      • Option 0: simple scaling factor
      • Option 1: use set of samples to estimate correlation rather than simple scaling factor
      • Option 2: exponential backoff
      • Option 3: Use NDVs for each field as a weighting mechanism (not sure if this is the approach described by Milena or not)
      • Option 4: Multi-field histograms (would require equality on prefix predicate?)

      The 4th option is out of scope for this ticket but would be worth considering down the line.

      Attachments

        Activity

          People

            backlog-query-optimization Backlog - Query Optimization
            nicholas.zolnierz@mongodb.com Nicholas Zolnierz
            Votes:
            0 Vote for this issue
            Watchers:
            2 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved: