Filter Strings
A filter string specifies criteria for the contents of an event. When you specify a filter string with an event subscription, the Broker uses the filter string to determine which events match your criteria. The Broker will place in your Broker client's event queue just the events that match the filter string.
Filter strings can do any combination of the following:
Refer to the content of event fields by using
field identifiers.
Compare event field contents against constants or computed values.
Combine event field comparisons using the boolean operators AND, OR, and NOT.
Perform arithmetic operations on event fields and constants.
Contain regular expressions.
Contain string and arithmetic constants.
Contain a hint that specifies how events should be processed.