View the implementation of your queries with Visual Explain

 

You can use the Visual Explain tool with iSeries™ Navigator to create a query graph that graphically displays the implementation of an SQL statement. You can use this tool to see information about both static and dynamic SQL statements. Visual Explain supports the following types of SQL statements: SELECT, INSERT, UPDATE, and DELETE.

Queries are displayed using a graph with a series of icons that represent different operations that occur during implementation. This graph is displayed in the main window. In the lower portion of the pane, the SQL statement that the graph is based on is displayed. If Visual explain is started from Run SQL Scripts, you can view the debug messages issued by the optimizer by clicking the Optimizer messages tab. The Query attributes are displayed in the right pane.

Visual Explain can be used to graphically display the implementations of queries stored in the detailed SQL performance monitor. However, it does not work with tables resulting from the memory-resident monitor.

• Starting Visual Explain
  There are two ways to invoke the Visual Explain tool. The first, and most common, is through iSeries Navigator. The second is through the Visual Explain (QQQVEXPL) API.

• Overview of information available from Visual Explain
  You can use Visual Explain to view many types of information.

 

Parent topic:

Optimizing query performance using query optimization tools