[HIVE-13806] Extension to folding NOT expressions in CBO

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.1.0
• Fix Version/s: 2.1.0
• Component/s: CBO
• Assignee: Jesús Camacho Rodríguez
• Reporter: Jesús Camacho Rodríguez
• Created: 20/May/16 15:24
• Updated: 27/Feb/24 22:23
• Resolved: 03/Jun/16 20:02

Description

Follow-up of HIVE-13068.

Extension to folding expressions for NOT.

Currently, simplification is performed only if NOT is applied on a simple operation (e.g. IS NOT NULL, =, <>, etc.). We should take advantage of NOT distributivity when it is applied on OR/AND operations to try to simplify predicates further.

Ex. ql/src/test/results/clientpositive/folder_predicate.q.out

explain
SELECT * FROM predicate_fold_tb WHERE not(value IS NOT NULL AND value = 3)

Plan:

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: predicate_fold_tb
            Statistics: Num rows: 6 Data size: 7 Basic stats: COMPLETE Column stats: NONE
            Filter Operator
              predicate: (not (value is not null and (value = 3))) (type: boolean)
              Statistics: Num rows: 3 Data size: 3 Basic stats: COMPLETE Column stats: NONE
              Select Operator
                expressions: value (type: int)
                outputColumnNames: _col0
                Statistics: Num rows: 3 Data size: 3 Basic stats: COMPLETE Column stats: NONE
                File Output Operator
                  compressed: false
                  Statistics: Num rows: 3 Data size: 3 Basic stats: COMPLETE Column stats: NONE
                  table:
                      input format: org.apache.hadoop.mapred.SequenceFileInputFormat
                      output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
                      serde: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe

  Stage: Stage-0
    Fetch Operator
      limit: -1
      Processor Tree:
        ListSink

Issue Links

• relates to: HIVE-13068 Disable Hive ConstantPropagate optimizer when CBO has optimized the plan II