This chapter provides an overview of object-relational data type descriptors.
This chapter includes the following section:
For information on descriptor concepts and features common to more than one type of TopLink descriptors, see Chapter 16, "Introduction to Descriptors".
The object-relational data type paradigm extends traditional relational databases to include object-oriented functions. Oracle, IBM DB2, Informix, and other DBMS databases allow users to store, access, and use complex data in more sophisticated ways.The object-relational data type standard is an evolving standard concerned mainly with extending the database data structures and SQL (SQL 3).
Object-relational data type descriptors describe Java objects that you map to special relational database types that correspond more closely to object types. Using these special object-relational data type database types can simplify mapping objects to relational database tables. Not all relational databases support these special object-relational data type database types.
Using object-relational data type descriptors in a relational project, you can configure object-relational data type mappings to these special object-relational data type database data types (see Section 40.1, "Object-Relational Data Type Mapping Types").
For more information, see the following: