SQL Optimizer automatically retrieves the execution plan when you optimize or execute a SQL statement. The Execution Plan window contains an Estimated Plan tab and an Actual Plan tab.
Note: When you generate virtual index alternatives, the execution plan is not retrieved for the SQL statement because SQL Optimizer does not physically create indexes on the database. See Fill Missing Estimated Plans for more information.
The Estimated Plan is generated by the SHOWPLAN command.
To get an estimated plan
Do one of the following:
- Click .
- Select the Estimated Plan tab and click Get Estimated Plan.
The Actual Plan is retrieved after executing SQL and includes real statistics such as Actual Rows, Actual Rebinds and Actual Rewinds that are not in an estimated plan.
To get an actual plan
» | To retrieve an Actual Plan, do one of the following: |
Execute the selected SQL statement.
For the selected statement, select the Actual Plan tab and click Test Run - Current.
Tips for both Estimated and Actual Plans:
Use the Plan toolbar (right side of pane in tree view) to select from several options that display different plan details (operators, predicates, statistics).
Note: The Actual Plan tab displays and additional button at the top of the Plan toolbar. Click the Plan Comparison button to display a comparison of estimates and actual statistics.
Right-click in the Execution Plan window to select from the following actions:
Action | Description |
Copy | Copies the execution plan to the clipboard. |
Save | Saves the execution plan as a JPG file. |
Opens the print window so you can print the execution plan. | |
Style |
Select option to display different plan details (operators, predicates, statistics). |
View Plan | Allows you to change how the execution plan is displayed. |
Step Description | Select this option to display a description of the step selected in the execution plan. |
Plan Information | If you select this option, SQL Optimizer identifies whether an execution plan uses any of the following: cardinality feedback, dynamic sampling, SQL plan directives, or adaptive plan. If applicable, the information displays in the Execution Plan pane directly above the Execution Plan tab. |
Animate Plan Steps | Highlights, one-by-one, the execution plan steps. |
View Missing Indexes | Create a user-defined alternative. |
Generate Indexes | Explore different index alternatives. |
Plan Options | Opens the Execution Plan Options window so you can select which information is displayed in the execution plan and whether to display specific items in a column. |
Help on SELECT | Displays definition of SELECT operator. |
Help on Execution Plan | Opens online help for the Execution Plan window. |
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