If you have a large amount of data and wish to do your tuning offline, it is a best practice to use the purge and database tuning features in the dbadmin.bat utility. To do this, you must stop the Manager and run the scripts.
A best practice suggestion is to wait for 97 days of data and then, on a recurring 7-day period, run the purge and the database tuning features in the dbadmin.bat utility.