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  1. IMPALA
  2. IMPALA-5586

Null-aware anti-join can take a long time to cancel

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: Impala 2.10.0
    • Fix Version/s: Impala 2.10.0
    • Component/s: Backend
    • Labels:

      Description

      Queries with a null-aware anti-join joining on a large number of NULLs can take a long time to cancel if threads are stuck in PartitionedHashJoinNode::EvaluateNullProbe().

      Reproduction:

      1. Run this query against tpch_parquet:
        select l_orderkey, l_partkey, l_suppkey, l_linenumber
        from lineitem
        where if(l_orderkey % 2 = 0, NULL, l_partkey) not in (
          select p_partkey
          from part
          where p_retailprice < l_extendedprice * l_tax)
        order by 1,2,3,4
        
      2. Cancel it
      3. See Impala still consuming CPU in EvaluateNullProbe() for a long time after cancellation

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            • Assignee:
              anujphadke Anuj Phadke
              Reporter:
              tarmstrong Tim Armstrong
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              Dates

              • Created:
                Updated:
                Resolved: