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  1. Hive
  2. HIVE-3652

Join optimization for star schema

    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major
    • Resolution: Duplicate
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: Query Processor
    • Labels:
      None

      Description

      Currently, if we join one fact table with multiple dimension tables, it results in multiple mapreduce jobs for each join with dimension table, because join would be on different keys for each dimension.
      Usually all the dimension tables will be small and can fit into memory and so map-side join can used to join with fact table.

      In this issue I want to look at optimizing such query to generate single mapreduce job sothat mapper loads dimension tables into memory and joins with fact table on different keys as well.

        Attachments

        1. HIVE-3652-tests.patch
          17 kB
          Amareshwari Sriramadasu
        2. HIVE-3652-tests.patch
          23 kB
          Amareshwari Sriramadasu

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              • Assignee:
                vikram.dixit Vikram Dixit K
                Reporter:
                amareshwari Amareshwari Sriramadasu
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                • Created:
                  Updated:
                  Resolved: