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  1. HBase
  2. HBASE-3855

Performance degradation of memstore because reseek is linear

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Details

    • Improvement
    • Status: Closed
    • Critical
    • Resolution: Fixed
    • None
    • 0.90.4
    • None
    • None
    • Reviewed

    Description

      The scanner use reseek to find the next row (or next column) as part of a scan. The reseek code iterates over a Set to position itself at the right place. If there are many thousands of kvs that need to be skipped over, then the time-cost is very high. In this case, a seek would be far lesser in cost than a reseek.

      Attachments

        1. memstoreReseek.txt
          3 kB
          Dhruba Borthakur
        2. memstoreReseek2.txt
          3 kB
          Dhruba Borthakur

        Issue Links

          relates to

          Improvement - An improvement or enhancement to an existing feature or task. HBASE-6334 TestImprovement for TestHRegion.testWritesWhileGetting

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Activity

            People

              Unassigned Unassigned
              dhruba Dhruba Borthakur
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              Dates

                Created:
                Updated:
                Resolved: