Optimization runs only once on all existing rules, then the profiles for the evaluated rules are stored in the log file. However, if you changed any deployed rule, the changed rule is evaluated and optimized again. Changes include adding and updating a rule, and disabling and re-enabling a rule.
When you no longer need the optimization feature, change the optimization setting to false in server.properties and, additionally in distributed correlation mode, correlator.properties (in all correlator instances if you have more than one).