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  1. Hive
  2. HIVE-9132 CBO: Calcite Operator To Hive Operator (Calcite Return Path)
  3. HIVE-10804

CBO: Calcite Operator To Hive Operator (Calcite Return Path): optimizer for limit 0 does not work

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Details

    • Sub-task
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 1.2.0
    • CBO
    • None

    Description

      explain
      select key,value from src order by key limit 0
      POSTHOOK: type: QUERY
      STAGE DEPENDENCIES:
        Stage-1 is a root stage
        Stage-0 depends on stages: Stage-1
      
      STAGE PLANS:
        Stage: Stage-1
          Map Reduce
            Map Operator Tree:
                TableScan
                  alias: src
                  Statistics: Num rows: 500 Data size: 5312 Basic stats: COMPLETE Column stats: NONE
                  Select Operator
                    expressions: key (type: string), value (type: string)
                    outputColumnNames: key, value
                    Statistics: Num rows: 500 Data size: 5312 Basic stats: COMPLETE Column stats: NONE
                    Reduce Output Operator
                      key expressions: key (type: string)
                      sort order: +
                      Statistics: Num rows: 500 Data size: 5312 Basic stats: COMPLETE Column stats: NONE
                      value expressions: value (type: string)
            Reduce Operator Tree:
              Select Operator
                expressions: KEY.reducesinkkey0 (type: string), VALUE.value (type: string)
                outputColumnNames: key, value
                Statistics: Num rows: 500 Data size: 5312 Basic stats: COMPLETE Column stats: NONE
                Limit
                  Number of rows: 0
                  Statistics: Num rows: 0 Data size: 0 Basic stats: NONE Column stats: NONE
                  File Output Operator
                    compressed: false
                    Statistics: Num rows: 0 Data size: 0 Basic stats: NONE Column stats: NONE
                    table:
                        input format: org.apache.hadoop.mapred.TextInputFormat
                        output format: org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat
                        serde: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe
      

      Attachments

        1. HIVE-10804.01.patch
          1 kB
          Pengcheng Xiong

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            pxiong Pengcheng Xiong
            pxiong Pengcheng Xiong
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            Dates

              Created:
              Updated:
              Resolved: