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  1. Hive
  2. HIVE-19684

Hive stats optimizer wrongly uses stats against non native tables

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    Description

      Stats of non native tables are inaccurate, thus queries over non native tables can not optimized by stats optimizer.
      Take example of query 

      Explain select count(*) from (select `__time` from druid_test_table limit 1) as src ;

      the plan will be reduced to 

      POSTHOOK: query: explain extended select count(*) from (select `__time` from druid_test_table limit 1) as src
POSTHOOK: type: QUERY
STAGE DEPENDENCIES:
  Stage-0 is a root stage
STAGE PLANS:
  Stage: Stage-0
    Fetch Operator
      limit: 1
      Processor Tree:
        ListSink

      Attachments

        1. HIVE-19684.patch
          4 kB
          Slim Bouguerra
        2. HIVE-19684.2.patch
          13 kB
          Slim Bouguerra
        3. HIVE-19684.3.patch
          15 kB
          Slim Bouguerra

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