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  1. IMPALA
  2. IMPALA-2080

Automatically gather row count stats during Create Table As Select

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Details

    • Improvement
    • Status: Resolved
    • Minor
    • Resolution: Won't Fix
    • Impala 2.2
    • None
    • Backend

    Description

      Problem Statement
      During ETL process or ad-hoc analysis, a temporary table is created using Create Table As Select (CTAS) and then read immediately by the subsequent query. However, the newly create temp table has no stats. Subsequent queries that read from the temp table can have an incorrect join order and join strategy.

      Potential Fix
      Given that row count is readily avaialble during CTAS and it's the most important fact in determining join order and join strategy, Impala should update the row count stats of the table created during CTAS.

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            Unassigned Unassigned
            alan@cloudera.com Alan Choi
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              Updated:
              Resolved:

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