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  1. Apache Trafodion (Retired)
  2. TRAFODION-1867

UPDATE STATS forces serial plans for non-partitioned tables

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Details

    • Bug
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 1.3-incubating, 2.0-incubating
    • 2.0-incubating
    • sql-cmu
    • None
    • All

    Description

      If one does an UPDATE STATISTICS for a non-partitioned table that is too large for internal sort, and does so without a SAMPLE clause, then UPDATE STATISTICS will perform SELECTs a few columns at a time, generating histograms on each. The plans are forced to be serial, even though the grouping and sorting phase could be done in parallel. This was evidently done as a workaround to a long-past compiler bug that seems to be fixed now. The serial plans slow down UPDATE STATISTICS, so it seems like it is time to remove the workaround code and let these plans be parallel.

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            dbirdsall Dave Birdsall
            dbirdsall Dave Birdsall
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            Dates

              Created:
              Updated:
              Resolved: