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  1. Hive
  2. HIVE-20187

Incorrect query results in hive when hive.convert.join.bucket.mapjoin.tez is set to true

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Details

    • Bug
    • Status: Resolved
    • Blocker
    • Resolution: Fixed
    • 3.1.0
    • None
    • None
    • None
    • Hive 3.0 and Tez 0.91

    Description

      When hive.convert.join.bucket.mapjoin.tez=true and bucketed column is in select clause but not in where clause, hive is performing a bucket map join and returning incorrect results. When the bucketed column is removed from select clause or  hive.convert.join.bucket.mapjoin.tez=false, returned query results are correct.

       

      create table my_fact(AMT decimal(20,3),bucket_col string ,join_col string )

      PARTITIONED BY (FISCAL_YEAR string ,ACCOUNTING_PERIOD string )
      CLUSTERED BY (bucket_col) INTO 10
      BUCKETS
      stored as ORC
      ;
      create table my_dim(join_col string,filter_col string) stored as orc;

      After populating and analyzing above tables, explain  plan looks as below when  hive.convert.join.bucket.mapjoin.tez=TRUE:

       

      explain  select T4.join_col as account1,my_fact.accounting_period
      FROM my_fact JOIN my_dim T4 ON my_fact.join_col = T4.join_col
      WHERE my_fact.fiscal_year = '2015'
      AND T4.filter_col IN ( 'VAL1', 'VAL2' )
      and my_fact.accounting_period in (10);

      Vertex dependency in root stage
      Map 1 <- Map 2 (CUSTOM_EDGE)

      Stage-0
      Fetch Operator
      limit:-1
      Stage-1
      Map 1 vectorized, llap
      File Output Operator [FS_24]
      Select Operator [SEL_23] (rows=15282589 width=291)
      Output:["_col0","_col1","_col2"]
      Map Join Operator [MAPJOIN_22] (rows=15282589 width=291)
      BucketMapJoin:true,Conds:SEL_21._col1=RS_19._col0(Inner),Output:["_col0","_col3","_col4"]
      <-Map 2 [CUSTOM_EDGE] vectorized, llap
      MULTICAST [RS_19]
      PartitionCols:_col0
      Select Operator [SEL_18] (rows=818 width=186)
      Output:["_col0"]
      Filter Operator [FIL_17] (rows=818 width=186)
      predicate(filter_col) IN ('VAL1', 'VAL2') and join_col is not null)
      TableScan [TS_3] (rows=1635 width=186)
      default@my_dim,t4,Tbl:COMPLETE,Col:NONE,Output:["join_col","filter_col"]
      <-Select Operator [SEL_21] (rows=13893263 width=291)
      Output:["_col0","_col1","_col3"]
      Filter Operator [FIL_20] (rows=13893263 width=291)
      predicate:join_col is not null
      TableScan [TS_0] (rows=13893263 width=291)
      default@my_fact,my_fact,Tbl:COMPLETE,Col:NONE,Output:["bucket_col","join_col"]

      extended_explain.txt has more detailed plan.

      When  hive.convert.join.bucket.mapjoin.tez=false,  plan no longer has bucketjoin and query results are correct.

      Vertex dependency in root stage
      Map 1 <- Map 2 (BROADCAST_EDGE)

      Stage-0
      Fetch Operator
      limit:-1
      Stage-1
      Map 1 vectorized, llap
      File Output Operator [FS_24]
      Select Operator [SEL_23] (rows=15282589 width=291)
      Output:["_col0","_col1","_col2"]
      Map Join Operator [MAPJOIN_22] (rows=15282589 width=291)
      Conds:SEL_21._col1=RS_19._col0(Inner),Output:["_col0","_col3","_col4"]
      <-Map 2 [BROADCAST_EDGE] vectorized, llap
      BROADCAST [RS_19]
      PartitionCols:_col0
      Select Operator [SEL_18] (rows=818 width=186)
      Output:["_col0"]
      Filter Operator [FIL_17] (rows=818 width=186)
      predicate(filter_col) IN ('VAL1', 'VAL2') and join_col is not null)
      TableScan [TS_3] (rows=1635 width=186)
      default@my_dim,t4,Tbl:COMPLETE,Col:NONE,Output:["join_col","filter_col"]
      <-Select Operator [SEL_21] (rows=13893263 width=291)
      Output:["_col0","_col1","_col3"]
      Filter Operator [FIL_20] (rows=13893263 width=291)
      predicate:join_col is not null
      TableScan [TS_0] (rows=13893263 width=291)
      default@my_fact,my_fact,Tbl:COMPLETE,Col:NONE,Output:

       

      Per suggestion in bug# TEZ-3971, creating this case under Hive project.

       

       

      Attachments

        1. extended_explain.txt
          12 kB
          Karthik
        2. HIVE-20187.1.patch
          4 kB
          Jaume M
        3. HIVE-20187.2.patch
          16 kB
          Deepak Jaiswal
        4. HIVE-20187.3.patch
          39 kB
          Deepak Jaiswal

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              djaiswal Deepak Jaiswal
              Palaniappan Karthik
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                Created:
                Updated:
                Resolved: