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  1. ORC
  2. ORC-397

ORC should allow selectively disabling dictionary-encoding on specified columns

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Details

    • New Feature
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 1.5.3, 1.6.0
    • None
    • None

    Description

      Just as ORC allows the choice of columns to enable bloom-filters on, it would be nice to have a way to specify which columns DICTIONARY_V2 encoding should be disabled on.

      Currently, the choice of dictionary-encoding depends on the results of sampling the first row-stride within a stripe. If the user knows that a column's cardinality is bound to prevent an effective dictionary, she might choose to simply disable it on just that column, and avoid the cost of sampling in the first row-stride.

      Attachments

        1. HIVE-18608.1-branch-2.2.patch
          10 kB
          Mithun Radhakrishnan
        2. HIVE-18608.2-branch-2.2.patch
          10 kB
          Mithun Radhakrishnan

        Issue Links

          is related to

          New Feature - A new feature of the product, which has yet to be developed. SPARK-25635 Support selective direct encoding in native ORC write

          • Major - Major loss of function.
          • Resolved

          New Feature - A new feature of the product, which has yet to be developed. ORC-308 Add function to get subtypes by name

          • Major - Major loss of function.
          • Closed

          Improvement - An improvement or enhancement to an existing feature or task. ORC-299 Improve heuristics for bailing on dictionary encoding

          • Major - Major loss of function.
          • Open
          links to

          Web Link GitHub Pull Request #304

          Activity

            People

              mithun Mithun Radhakrishnan
              mithun Mithun Radhakrishnan
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              Dates

                Created:
                Updated:
                Resolved: