Page History
...
- The Playback controls, located at the top of the tree, enable you to freely move within the execution plan of an explained statement (step by step).
- By moving the pointer over the execution plan steps, you can view a ToolTip that contains statistical information, such as Estimated Cost, Estimated Rows, and Estimated I/O Cost, and a description of the specified step.
- Selecting a specific step (operator) highlights nested steps and affects the information displayed in the Detail tabs: the relevant Optimized text is shown on the Highlights tab; the referenced tables, indexes, and columns are shown on the Objects tab; the operators and predicates are shown on the Operators tab; and the Original text is shown on the Text tab. The Recommendations tab, only displayed when you generate recommendations, shows index details and the DDL for creating the indexes.
- Clicking the hatchet mark (
), located at the bottom of the tree, displays the Tree View area with three tabs allowing you to select which statement text to view:- Optimized Text
- Original Text
- Remote Query Text
...
Table 7-5 Columns in table
Column Description
...
| Column | Description |
|---|---|
 | Click to launch to Objects tab—with the selected table in context—to get additional catalog information about the object. |
 |
...
| The column definition in the chosen index (Ascending, Descending, or Included). |
| Column |
...
| Column name. |
| Type |
...
| Data type of the column. |
| Length |
...
| The length of the column. |
| Key |
...
| Number | The position within the chosen index. |
| Anchor | ||||
|---|---|---|---|---|
|
...
The following table describes the information displayed in the Operators table.
Table 7-6 Operators table
Column Description
...
| Column | Description |
|---|---|
 | Click to locate and highlight in Bold font the same operator in the execution plan. |
| Operator |
...
| ID | Operator ID issued by the DB2 Optimizer. |
| Execution |
...
| Order | The execution order of operators in the plan. |
| Operator |
...
| Operator type. |
| Subtree Total |
...
| Cost | The total cost of this operator subtree. |
| Cost(%) |
...
| The percentage cost of this operator in the plan. | |
| First Row |
...
| Cost | First row cost of the operator subtree. |
| I/O |
...
| Cost | I/O Cost. |
| CPU |
...
| Cost | CPU Cost. |
| Prefetch |
...
| Prefetch type. |
| Estimated |
...
| Rows | The estimated rows of the operator. |
| Estimated |
...
| Pages | The estimated pages of the operator. |
| Potential Filter |
...
| Factor | Potential filter factor calculated by the predicate’s filter factor of the operator. |
| Table |
...
| Partitions | The estimated number of table partitions to be accessed. |
The following table describes the information displayed in the Predicates table.
Table 7-7 Predicates table
Column Description
...
| Column | Description |
|---|---|
| Text | Predicate text. |
| Filter |
...
| Factor | The estimated filter factor of the predicate. |
| How Applied | How |
...
| predicate is being used by the specified operator. |
| Sub |
...
| Select | Indicates when the subquery used in this predicate is evaluated. |
| Anchor | ||||
|---|---|---|---|---|
|
...
Table 7-8 Recommendations table
Column Description
...
| Column | Description |
|---|---|
| Object | The name of the index. |
...
| Actions | Create index. |
| Columns |
...
| Columns participating in the index or Include Columns in the index. |
The Details area displays statistical information of the recommended index. The DDL area displays the create index statement.
...
Use the Actions menu to perform the following operations:
- Creating a new statement
- Opening an existing statement
- Editing an existing statement
- Re-explaining an access plan
- Generating recommendations
| Anchor | ||||
|---|---|---|---|---|
|
You can create a new statement and save it in the PMDB in a logical cabinet and folder hierarchy. You can also rewrite statements and view their access plans.
...
The new statement is saved in the PMDB in a logical cabinet and folder hierarchy.
| Anchor | ||||
|---|---|---|---|---|
|
You can load a previously saved statement. To open an existing statement
- On the Actions menu, click Open. The Open Statement dialog box is displayed.
- In the Open Statement dialog box, select the statement you want to open by choosing its relevant properties from the drop-down lists, as follows:
- Database. The name of the database where the statement is running.
- Cabinet. Cabinet The The name of the cabinet that the statement is saved in.
- Folder. Folder The The name of the folder that the statement is saved in.
- Statement. Statement The The name of the statement.
- Comment. Displays free text entered by the user.
The statement's text is displayed in the Text frame.
- Click OK.
| Info |
|---|
...
If the SQL tab is opened with no statement in-context, the following error message is displayed:
To open a statement you can close the error message dialog and click the Open button displayed on the upper right-hand side of the Details area or click Actions>Open. To open a new statement click Actions>New. |
| Anchor | ||||
|---|---|---|---|---|
|
You can edit a statement that was saved in the PMDB. The statement that was collected by the Collector is saved as a new statement in a logical cabinet and folder hierarchy.
...
- On the Actions menu, click Edit.
- In the Edit Statement dialog box, select the statement you want to edit by choosing its relevant properties from the drop-down lists, as follows:
- Database. The name of the database where the statement is running.
- User. The statement's parsing user.
- Cabinet. The name of the cabinet that the statement is saved in.
- Folder. Folder The The name of the folder that the statement is saved in.
- Statement. The name of the statement.
- Comment. Displays free text entered by the user.
- Enter a new statement name in the Statement field.
- Edit the SQL text for the statement in the Text frame.
- Click OK.
The edited statement is saved in a logical cabinet and folder hierarchy.
| Anchor | ||||
|---|---|---|---|---|
|
You can refresh a statement plan by generating a new estimated access plan and saving it, if it is different from the most recent access plan. You can then display the most recent access plan.
To re-explain a statement, go to Actions>Re-Explain or, alternatively, click the Re-Explain button.
| Anchor | ||||
|---|---|---|---|---|
|
You can generate new index recommendations for the statement. These are additional indexes that can improve the statement.
To generate a recommendation, go to Actions>Recommend or, alternatively, click the Recommend button.
...