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  1. Ignite
  2. IGNITE-14635

Calcite engine. EXCEPT operator using anti-join

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Details

    • Improvement
    • Status: Open
    • Minor
    • Resolution: Unresolved
    • None
    • None
    • None

    Description

      Currently, EXCEPT operator implemented as hash aggregation of underlying inputs, but in some cases ([all=false], inputs are colocated and have required collations) perhaps anti-join will be more effective (but benchmarking is needed) and produce streamed output.

      For example, query like SELECT f1 FROM t1 EXCEPT SELECT f1 FROM t2 could be rewritten to SELECT DISTINCT f1 FROM t1 ANTI JOIN t2 USING (f1).

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          is part of

          New Feature - A new feature of the product, which has yet to be developed. IGNITE-12248 Apache Calcite based query execution engine

          • Major - Major loss of function.
          • Open
          is related to

          Improvement - An improvement or enhancement to an existing feature or task. IGNITE-13691 Calcite Integration. Support of EXCEPT operator

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved

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              Unassigned Unassigned
              alex_pl Aleksey Plekhanov
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              Dates

                Created:
                Updated: