Define an operator class for other secondary-access methods
When you define an operator class on a user-defined secondary-access method, you provide support and strategy functions just as you do when you create an operator class on the generic B-tree index. You must be careful to conform to any operator class requirements of the user-defined secondary-access class. Before you implement an operator class for a user-defined secondary-access method, consult the documentation for the method.
You perform the same steps to define an operator class on a user-defined secondary-access method as you use to define an operator class on the generic B-tree index. (See Creating a new B-tree operator class.) The only difference is that to create the index, you must specify the name of the user-defined secondary-access method in the USING clause of the CREATE INDEX statement.