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  1. Apache Tez
  2. TEZ-2104

A CrossProductEdge which produces synthetic cross-product parallelism

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    Details

    • Type: New Feature
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.9.1
    • Component/s: None

      Description

      Instead of producing duplicate data for the synthetic cross-product, to fit into partitions, the amount of net IO can be vastly reduced by a special purpose cross-product data movement edge.

      The Shuffle edge routes each partition's output to a single reducer, while the cross-product edge routes it into a matrix of reducers without actually duplicating the disk data.

      A partitioning scheme with 3 partitions on the lhs and rhs of a join operation can be routed into 9 reducers by performing a cross-product similar to

      (1,2,3) x (a,b,c) = [(1,a), (1,b), (1,c), (2,a), (2,b) ...]

      This turns a single task cross-product model into a distributed cross product.

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            • Assignee:
              zhiyuany Zhiyuan Yang
              Reporter:
              gopalv Gopal Vijayaraghavan

              Dates

              • Created:
                Updated:
                Resolved:

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