Hive
  1. Hive
  2. HIVE-6643

Add a check for cross products in plans and output a warning

    Details

    • Type: Bug Bug
    • Status: Resolved
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.13.0
    • Component/s: None
    • Labels:
      None
    • Release Note:
      Added new config parameter 'hive.exec.check.crossproducts' to warn about Cross Products. By default this check is on.

      Description

      Now that we support old style join syntax, it is easy to write queries that generate a plan with a cross product.
      For e.g. say you have A join B join C join D on A.x = B.x and A.y = D.y and C.z = D.z
      So the JoinTree is:

      A — B

      __ D — C

      Since we don't reorder join graphs, we will end up with a cross product between (A join B) and C

      1. HIVE-6643.7.patch
        167 kB
        Harish Butani
      2. HIVE-6643.6.patch
        167 kB
        Harish Butani
      3. HIVE-6643.5.patch
        161 kB
        Harish Butani
      4. HIVE-6643.4.patch
        135 kB
        Harish Butani
      5. HIVE-6643.3.patch
        125 kB
        Harish Butani
      6. HIVE-6643.2.patch
        125 kB
        Harish Butani
      7. HIVE-6643.1.patch
        124 kB
        Harish Butani

        Activity

          People

          • Assignee:
            Harish Butani
            Reporter:
            Harish Butani
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            Dates

            • Created:
              Updated:
              Resolved:

              Development