Distinct data types

A distinct data type is a copy of another data type; it has an internal and external representation identical to its source data type, but the database server treats it as a different data type. Any existing routines on the source data type are automatically registered on the distinct data type. However, you can define new routines that operate only on the distinct data type.

You can define custom support routines and user-defined routines for your distinct data type. You can also overload existing user-defined routines and built-in routines to work on your distinct type.