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  1. Hadoop Map/Reduce
  2. MAPREDUCE-1489

DataDrivenDBInputFormat should not query the database when generating only one split

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Details

    • Improvement
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 0.21.0
    • None
    • None
    • Reviewed

    Description

      DataDrivenDBInputFormat runs a query to establish bounding values for each split it generates; but if it's going to generate only one split (mapreduce.job.maps == 1), then there's no reason to do this. This will remove overhead associated with a single-threaded import of a non-indexed table since it avoids a full table scan.

      Attachments

        1. MAPREDUCE-1489.patch
          11 kB
          Aaron Kimball

        Issue Links

          depends upon

          Improvement - An improvement or enhancement to an existing feature or task. MAPREDUCE-1460 Oracle support in DataDrivenDBInputFormat

          • Major - Major loss of function.
          • Closed
          is depended upon by

          Improvement - An improvement or enhancement to an existing feature or task. MAPREDUCE-1502 Sqoop should run mysqldump in a mapper as opposed to a user-side process

          • Major - Major loss of function.
          • Resolved

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              kimballa Aaron Kimball
              kimballa Aaron Kimball
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              Dates

                Created:
                Updated:
                Resolved: