Hadoop Common
  1. Hadoop Common
  2. HADOOP-3308

Improve QuickSort by excluding values eq the pivot from the partition

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.18.0
    • Component/s: None
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      The current implementation of QuickSort naively partitions on either side of the pivot. We can improve this by partitioning on either side of the set of values equal to the pivot. This assumes that comparing keys is expensive compared to swaps and index comparisons (which it certainly is in MapTask, and should be in general).

      1. 3308-2.patch
        6 kB
        Chris Douglas
      2. 3308-1.patch
        5 kB
        Chris Douglas
      3. 3308-0.patch
        5 kB
        Chris Douglas

        Activity

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          People

          • Assignee:
            Chris Douglas
            Reporter:
            Chris Douglas
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            Dates

            • Created:
              Updated:
              Resolved:

              Development