In any business, there are many entities or objects. There is no default way to represent a business object in a database. For example, currency is a business entity and there is such a thing in the database that can represent currency directly. To support such requirements, DB2 provides user-defined types (also known as UDTs). A user-defined type is a data type which is derived from the existing data types and is treated as a separated data type.

As a user, we can define our own data types based on in-built data types provided by DB2. A simple example would be, we can define USD as DECIMAL (10, 2) and use this across our application or schema. Similarly, we can define a type as CLOB(32K) and resume, and so on. Even if we define multiple user-defined types based on the same underlying DB2 data type, they are still treated as separate data types. The key advantage of such a design is consistency. Because we can define our own data type for a business...