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  1. Pig
  2. PIG-4002

Disable combiner when map-side aggregation is used

    Details

    • Type: Improvement
    • Status: Patch Available
    • Priority: Minor
    • Resolution: Unresolved
    • Affects Version/s: 0.13.0
    • Fix Version/s: 0.18.0
    • Component/s: None
    • Labels:
      None

      Description

      This may be controversial, so I'd like others' opinions on this.

      It is not currently possible to disable the combiner and use map-side aggregation at the same time. This is a problematic since map-side aggregation effectively combines in the mapper, so running the combiner adds expensive combiner execution (combiner requires deserialization & reserialization) for little to no value.

      PIG-2829 had a patch to disable the combiner when map-side aggregation is used (along with some other changes). This was never integrated because the map-side aggregation code was redone while this was in progress.

        Attachments

        1. PIG-4002-1.patch
          5 kB
          Travis Woodruff

          Activity

            People

            • Assignee:
              tmwoodruff Travis Woodruff
              Reporter:
              tmwoodruff Travis Woodruff
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              Dates

              • Created:
                Updated: