1) always run an Application Optimizer "preview" analysis first on any long running batch job. Only do this if it is a job that starts and finishes. Not for never ending server jobs.

2) if the "preview" data shows any QSQ or QQQ operating system programs, stop using Application Optimizer and switch to the Query Optimizer. The Application Optimizer should only be used for RPG, COBOL, CL, C and JAVA code. The Query Optimizer should be used on any job that runs SQL or queries.

3) run an Application Optimizer "trace" or "source" analysis on a Development or Test system only to perform operating system and source level analysis. These data collections can dramatically impact the performance of the job and the system. Normally, should not be run on Production.