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  1. Calcite
  2. CALCITE-545

When a projected expression can only have one value, replace with that constant

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 1.0.0-incubating
    • Component/s: None
    • Labels:
      None

      Description

      When we have deduced that an expression can only have one value, replace the expression with that value. This is beneficial because it will allow us to do more column trimming.

      Example 1

      select deptno from emp where deptno = 10

      can become

      select 10 from emp where deptno = 10

      Example 2 (using inference, as in CALCITE-360)

      select emp.deptno
      from emp join dept using (deptno)
      where dept.deptno = 10

      can become

      select 10
      from emp join dept using (deptno)
      where dept.deptno = 10

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            • Assignee:
              julianhyde Julian Hyde
              Reporter:
              julianhyde Julian Hyde
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              • Created:
                Updated:
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