Uploaded image for project: 'Phoenix'
  1. Phoenix
  2. PHOENIX-2724

Query with large number of guideposts is slower compared to no stats

    XMLWordPrintableJSON

Details

    • Bug
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 4.7.0
    • 4.8.0
    • None
    • None

    • Phoenix 4.7.0-RC4, HBase-0.98.17 on a 8 node cluster

    Description

      With 1MB guidepost width for ~900GB/500M rows table. Queries with short scan range gets significantly slower.

      Without stats:

      select * from T limit 10; // query execution time <100 msec

      With stats:

      select * from T limit 10; // query execution time >20 seconds

Explain plan: CLIENT 876085-CHUNK 476569382 ROWS 876060986727 BYTES SERIAL 1-WAY FULL SCAN OVER T SERVER 10 ROW LIMIT CLIENT 10 ROW LIMIT

      Attachments

        1. 2724.txt
          3 kB
          Lars Hofhansl
        2. PHOENIX-2724_addendum.patch
          6 kB
          Samarth Jain
        3. PHOENIX-2724_v2.patch
          36 kB
          Samarth Jain
        4. PHOENIX-2724.patch
          29 kB
          Samarth Jain

        Issue Links

          is related to

          Bug - A problem which impairs or prevents the functions of the product. PHOENIX-3043 Tune table options for SYSTEM.STATS

          • Major - Major loss of function.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. PHOENIX-3040 Don't use guideposts for executing queries serially

          • Major - Major loss of function.
          • Closed

          Activity

            People

              larsh Lars Hofhansl
              mujtabachohan Mujtaba Chohan
              Votes:
              0 Vote for this issue
              Watchers:
              9 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: