About event types introduced event type classes.

The correlator creates several indexing data structures for every event type. The complexity and efficiency of these data structures depends on the number of parameters an event has, and therefore ‘smaller' (with less parameters) events are processed more rapidly.

Therefore, if possible, when designing an application it is preferable to control it using a number of ‘smaller' event types rather than through a single event type with a large number of parameters.