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  1. Ignite
  2. IGNITE-16493

Calcite engine. Decorrelation after subquery rewrite

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      Currently decorrelation is performed in SqlToRelConverter, but after this PlannerPhase.HEP_DECORRELATE planning phase is executed (which actually rewrites subqueries into correlates, but doesn't perform decorrelation). In some cases, other types of join can cost less than correlated nested loop join, so we can try to decorrelate the query plan again after PlannerPhase.HEP_DECORRELATE phase (call RelDecorrelator.decorrelateQuery).
      PlannerPhase.HEP_DECORRELATE should be also renamed to something like "HEP_REWRITE_SUBQUERY".

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          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
          relates to

          Improvement - An improvement or enhancement to an existing feature or task. IGNITE-22092 Sql. Implement subquery decorrelation

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Open

          Task - A task that needs to be done. IGNITE-21579 Sql. Investigate performance bottlenecks in sql engine

          • Major - Major loss of function.
          • Resolved
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          Web Link GitHub Pull Request #9832

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              Unassigned Unassigned
              alex_pl Aleksey Plekhanov
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