You can evaluate the structure and performance of the given SQL statements in a program using informational messages put in the job log by the database manager.
The messages are issued for an SQL program or interactive SQL when running in the debug mode. The database manager may send any of the following messages when appropriate. The ampersand variables (&1, &X) are replacement variables that contain either an object name or some other substitution value when the message appears in the job log. These messages provide feedback on how a query was run and, in some cases, indicate the improvements that can be made to help the query run faster.
The messages contain message help that provides information about the cause for the message, object name references, and possible user responses.
The time at which the message is sent does not necessarily indicate when the associated function was performed. Some messages are sent altogether at the start of a query run.