Uploaded image for project: 'Derby'
  1. Derby
  2. DERBY-6134

Faster, incremental implementation of DISTINCT in presence of FETCH NEXT clause

    XMLWordPrintableJSON

    Details

    • Type: Improvement
    • Status: Open
    • Priority: Minor
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: SQL
    • Urgency:
      Low

      Description

      DISTINCT queries with a FETCH NEXT clause can be made faster
      by using a hash table rather than the current sorting of all rows, cf. the slow query seen by a user in DERBY-6132, at least if the number of rows fetched by the clause is a (low) fraction of the total number of rows and the has table would fit in memory.

        Attachments

          Issue Links

            Activity

              People

              • Assignee:
                Unassigned
                Reporter:
                dagw Dag H. Wanvik
              • Votes:
                1 Vote for this issue
                Watchers:
                3 Start watching this issue

                Dates

                • Created:
                  Updated: