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  1. Calcite
  2. CALCITE-6817

Add string representation of default nulls direction for RelNode

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Details

    • Improvement
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 1.38.0
    • 1.39.0
    • core

    Description

      Calcite has the same hehavior with Oracle on returning the null direction if not specified, which means NULLS LAST is assumed for ASC and NULLS FIRST is assumed for DESC.
      However, the default nulls direction is not presented in plan traces. For example:

      select empno from emp order by empno desc

      has the following plan:

      LogicalSort(sort0=[$0], dir0=[DESC])
  LogicalProject(EMPNO=[$0])
    LogicalTableScan(table=[[CATALOG, SALES, EMP]])

      It makes RelNode clearer if adding nulls direction, so the above plan will be like:

      LogicalSort(sort0=[$0], dir0=[DESC-nulls-first])
  LogicalProject(EMPNO=[$0])
    LogicalTableScan(table=[[CATALOG, SALES, EMP]])

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          is related to

          Bug - A problem which impairs or prevents the functions of the product. CALCITE-6798 Null direction emulation in MySQL and Hive is incorrect when null direction is not specified

          • Major - Major loss of function.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. CALCITE-970 If NULLS FIRST/LAST not specified, sort NULL values HIGH

          • Major - Major loss of function.
          • Closed
          links to

          Web Link GitHub Pull Request #4184

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              VAE ZheHu
              VAE ZheHu
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              Dates

                Created:
                Updated:
                Resolved: