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  1. Tajo
  2. TAJO-1275

Optimizer pushs down non-equi filter as theta join qualifier

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.10.0
    • Component/s: None
    • Labels:
      None

      Description

      Plan rewriter pushes down filters to leaf node as possible and changes filter condition to join qualifier if possible.

      Even though Tajo does not support theta-join completely, however,
      it pushes down non-equi compare and makes it as join qualifier sometimes.

      For example,

      select * from (select a.r_name as a_name, b.c_name as c_name from region a, customer b) xx where a_name < c_name
      

      is rewritten as

      select a.r_name as a_name, b.c_name as c_name from region a join customer b on a.r_name < b.c_name
      

      And

      select * from region a join customer b on a.r_regionkey = b.c_custkey where a.r_name < c.c_name
      

      is rewritten as

      select * from region a join customer b on a.r_regionkey = b.c_custkey and a.r_name < c.c_name
      

      Until TAJO-742 is resolved (that means theta join is supported),
      I think it should not be allowed to rewrite non-equi filter condition as join qualifier.

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            • Assignee:
              sirpkt Keuntae Park
              Reporter:
              sirpkt Keuntae Park
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              Dates

              • Created:
                Updated:
                Resolved: