Details

    • Type: New Feature New Feature
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.19.0
    • Component/s: None
    • Labels:
      None
    • Hadoop Flags:
      Reviewed
    • Release Note:
      Introduced "EXPLAIN" plan for Hive.

      Description

      Adding explain plan for queries in hive.

      The current proposal is to support something like:

      EXPLAIN [EXTENDED]
      SELECT ....

      This will output the following:

      Abstract Syntax Tree:

      Number of Stages:

      Dependencies between Stages:

      Plan for each stage:

      If EXTENDED keyword is used then much more information will be emitted where as without that keyword only logical information will be emitted.

      e.g. In case of a group by query

      EXPLAIN
      SELECT T.c1, count(1) FROM T GROUP BY T.c1;

      The explain plan itself has two stages

      Stage1 and Stage2

      Stage1 will have the plan for generating the partial aggregates
      and Stage2 will have the plan for generating the complete aggregates.

      I also plan to convert the parse and semantic analysis tests so that they use this for finding differences in the plan instead of the programmatic plan dumps that we are using today (tests/queries/positive).

      1. patch-4084
        464 kB
        Ashish Thusoo
      2. patch-4084
        464 kB
        Ashish Thusoo
      3. patch-4084_v3
        544 kB
        Ashish Thusoo

        Activity

        Owen O'Malley made changes -
        Component/s contrib/hive [ 12312455 ]
        Nigel Daley made changes -
        Status Resolved [ 5 ] Closed [ 6 ]
        Robert Chansler made changes -
        Release Note Explain plan for hive Introduced "EXPLAIN" plan for Hive.
        dhruba borthakur made changes -
        Resolution Fixed [ 1 ]
        Status Patch Available [ 10002 ] Resolved [ 5 ]
        Ashish Thusoo made changes -
        Status Open [ 1 ] Patch Available [ 10002 ]
        Ashish Thusoo made changes -
        Status Patch Available [ 10002 ] Open [ 1 ]
        Ashish Thusoo made changes -
        Attachment patch-4084_v3 [ 12390313 ]
        Ashish Thusoo made changes -
        Status Open [ 1 ] Patch Available [ 10002 ]
        Fix Version/s 0.19.0 [ 12313211 ]
        Hadoop Flags [Reviewed]
        Ashish Thusoo made changes -
        Attachment patch-4084 [ 12390212 ]
        Ashish Thusoo made changes -
        Field Original Value New Value
        Attachment patch-4084 [ 12390035 ]
        Ashish Thusoo created issue -

          People

          • Assignee:
            Ashish Thusoo
            Reporter:
            Ashish Thusoo
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            0 Vote for this issue
            Watchers:
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            Dates

            • Created:
              Updated:
              Resolved:

              Development