View Optimization Details

SQL Optimizer for IBM DB2 z/OS

View Optimization Details

Note: This topic focuses on information that may be unfamiliar to you. It does not include all step and field descriptions.

To view optimization details

  1. Select the SQL Details tab in the main window.
  2. In the Alternatives pane, click .
  3. Select the SQL Information tab in the Optimize SQL window. Review the following for additional information:

    Optimization Details Description

    Intelligence level

    Intelligence level used for optimization. This option is set on the Optimizer Intelligence options page. Intelligence Options

    Semantically equivalent SQL statements

    Number of semantically equivalent SQL statements generated by SQL Optimizer.

    Alternative execution plans produced

    Number of alternative execution plans produced for the original SQL statement.

    SQL statements eliminated due to identical execution plans

    Number of statement alternatives eliminated with the same execution plan as the original SQL statement.

    Note: SQL statements with the same execution plan produce the same run time because the database executes these statements in the same way. Therefore, SQL Optimizer eliminates alternatives with equivalent execution plans.

    Optimization Time Details Description

    Optimization started at

    Time optimization started.

    Optimization finished at

    Time optimization finished.

    Total optimization time

    Total time to complete optimization.

    Average optimization time

    Average time to generate each statement alternative.

    Notes:

    • This information is only available after you generate SQL alternatives.
    • Optimization details only display for the original SQL statement.