Uploaded image for project: 'Derby'
  1. Derby
  2. DERBY-4327

Implement optimizer support for bushy trees.

    XMLWordPrintableJSON

Details

    • Improvement
    • Status: Open
    • Major
    • Resolution: Unresolved
    • None
    • None
    • SQL
    • Normal
    • Performance, Seen in production

    Description

      Currently, the optimizer only considers left-deep trees. For queries involving many tables, the best plan may be bushy. In this email thread, a user notes poor performance by Derby on queries involving 5 or more tables: http://www.nabble.com/Slow-performance-on-5-or-more-joins-in-a-star-schema-tt24708686.html

      Attachments

        Issue Links

          is related to

          Improvement - An improvement or enhancement to an existing feature or task. DERBY-1907 Improve optimizer to prune query plans more aggressively.

          • Major - Major loss of function.
          • Open

          Activity

            People

              Unassigned Unassigned
              rhillegas Richard N. Hillegas
              Votes:
              2 Vote for this issue
              Watchers:
              4 Start watching this issue

              Dates

                Created:
                Updated: