[HIVE-10804] CBO: Calcite Operator To Hive Operator (Calcite Return Path): optimizer for limit 0 does not work

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0
• Component/s: CBO
• Assignee: Pengcheng Xiong
• Reporter: Pengcheng Xiong
• Created: 22/May/15 22:44
• Updated: 05/Nov/15 16:58
• Resolved: 28/May/15 20:56

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