Predicate Analysis

The SQL Predicate Analysis screen (SQL Predicate Analysis) displays when you select option 3 from one of the Analysis screens. (See Plan Table Analysis Screen for more information on the Plan Table Analysis screen.) The predicates are analyzed to determine if they are indexable, stage I, or both. Based on the analysis, recommendations for improving the SQL performance are made. A long message is also provided for more detailed information. See Predicate-Analysis-Rules-Abbreviations for a complete list of the short and long messages.

The SQL statements for which there is a recommendation is highlighted in white. Recommendations for performance improvement immediately follow the SQL statement. The recommendations are highlighted and suffixed according to their severity as follows:

• Mandatory: highlighted green and suffixed with an M
• Severe: highlighted red and suffixed with an S
• Warning: highlighted yellow and suffixed with a W
• Informational: highlighted white and suffixed with an I

SQL Predicate Analysis

Additional Recommendation Information

The Predicate Analysis screen is cursor sensitive. Tab to any rule and press Enter to receive more information (see the following figure).

SQL Predicate Analysis — Detail Recommendation Information

Executing the SQL Command

When you execute the SQL primary command, a temporary data set containing the SQL source is created (see the following figure). An ISPF/PDF edit session is initiated enabling you to edit the SQL. If you want to save the data set, you must use the ISPF/PDF CREATE or COPY command before exiting the window.

When you END from this screen, the SQL is automatically reexplained and the SQL Analysis Summary screen displays.

Edit session initiated after executing the SQL command