You can create additional pre-change or post-change SQL trials for a SQL Performance Analyzer task to test if other system changes have resulted in changes to the execution plans of SQL statements and have impacted SQL performance.

1. Go to the SQL Performance Analyzer Task: <name of the task> panel.
2. In the Trials section, click Create trial.
3. In the Create trial panel:
   1. Review the SQL Performance Analyzer task details.
   2. Specify the following general options:
      1. Name: Enter a name for the trial.
      2. Description: Optionally, enter a description for the trial.
      3. Execution method: Select one of the following options to determine how the SQL trials are created and what content is generated:
         • Execute SQL: Generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements. On selecting this option, the Per SQL time limit field is displayed and you must select an option to specify the time limit for SQL execution during the trial.
         • Generate plans: Invokes the optimizer to create execution plans only without actually running the SQL statements.
   3. Select the check box in the Comparison section to understand how the trial's performance compares with a reference trial. On selecting the check box, the following fields are displayed:
      1. Reference trial: Select a reference SQL trial for comparison and review the details of the trial.
      2. Comparison metric: The comparison metric selected for the reference trial is displayed by default and you can change or add other metrics for the analysis. If you chose to generate explain plans only in the SQL trial, the Optimizer cost metric stored in the SQL execution plans is selected by default.
      3. Validate SQL result sets: Select to direct the SQL Performance Analyzer to detect if the result-sets between the two trials being compared are different. If differences are seen in the result-sets of any SQL statement between the two trials being compared, the SQL Performance Analyzer comparison report will indicate this for every such SQL statement. This is On by default.
   4. Schedule: Select Immediately to start the trial now or Later to schedule the trial at a later time.
4. Click Create.

You can create additional comparisons for a SQL Performance Analyzer task to compare the performance data collected in a pre-change SQL trial to the post-change SQL trial.

1. Go to the SQL Performance Analyzer Task: <name of the task> panel.
2. In the Comparisons section, click Create comparison.
3. In the Create comparison panel:
   1. Review the SQL Performance Analyzer task details.
   2. Select a reference SQL trial (pre-change) for comparison from the Reference trial drop-down list.
   3. Select a changed SQL trial (post-change) for comparison from the Changed trial drop-down list.
   4. Select the comparison metric in the Trial comparison field, based on which the pre-change and post-change trials will be compared.
   5. Select Immediately to start the comparison now or Later to schedule the comparison at a later time.
4. Click Create.