I don’t know either of these packages well, but I can give you some generic SQL improvments. The real goal is to make sure the system uses the SQE engine instead of the older CQE engine.
(1) Find file QUSRSYS/QAQQINI. If it doesn’t exist, use CRTDUPOBJ to duplicate the one in QSYS. Look for an entry IGNORE_DERIVED_INDEX and make sure its set to *YES. This prevents the SQE engine from rejecting the query (and sending it back to CQE) just becuase one index can’t be used.
(2) Take a common query and paste it into Visual Explain. It will suggest and help you build any indexes that may improve performance.
These suggestions are for V5r4. What release of the OS are you on ?