Uploaded image for project: 'Core Server'
  1. Core Server
  2. SERVER-23408

Use a smarter batch size for small samples

    XMLWordPrintableJSON

Details

    • Query Optimization
    • ALL
    • Query 2017-08-21, Query 2017-09-11

    Description

      In cases where we can use the optimized sampling from a random cursor, the DocumentSourceCursor will still use the default batch size. This can significantly slow down small sample sizes.

      Unfortunately, we cannot just pass down a limit to the DocumentSourceCursor, since the random cursor may give back duplicate documents, in which case we'd need to ask for more.

      Attachments

        Issue Links

          is duplicated by

          Bug - A problem which impairs or prevents the functions of the product. SERVER-23661 $sample takes disproportionately long time on newly created collection

          • Major - P3 - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. SERVER-30342 Slow performance of $project in aggregation pipeline in 3.4.6

          • Major - P3 - Major loss of function.
          • Closed

          Activity

            People

              backlog-query-optimization Backlog - Query Optimization
              charlie.swanson@mongodb.com Charlie Swanson
              Votes:
              3 Vote for this issue
              Watchers:
              25 Start watching this issue

              Dates

                Created:
                Updated: