|Oracle9i Application Developer's Guide - Object-Relational Features
Release 2 (9.2)
Part Number A96594-01
This section describes the new object-relational features of Oracle9i Release 2 (9.2) - BETA.
Synonyms can be defined for user-defined types so that a type can be used without having to qualify its name with the name of the schema in which the type was defined.
User-defined constructor functions make possible custom initialization of newly created object instances. They also make it possible to evolve a type without having to update calls to constructors in existing code to accommodate a newly added attribute.
Specialized versions of user-defined types can be defined as subtypes in a SQL type hierarchy.
Hierarchies can be created of object views based on some or all of the types in a type hierarchy. Object view hierarchies simplify targeting a particular subtype (and perhaps its subtypes) in queries and other operations.
User-defined SQL types can be changed, or evolved, instead of having to be re-created.
Custom aggregate functions can be defined for working with complex data.
External procedures can be given fields or parameters of a generic type that can contain values of any scalar or user-defined type, making it unnecessary to implement multiple versions of the same external procedure just to handle multiple datatypes.
Function-based indexes can be built on type method functions.
Collections (varrays and nested tables) can contain elements that are themselves collections or have attributes that are.
A C++ interface (OCCI) to Oracle, built on top of OCI, enables you to use the object-oriented features, native classes, and methods of the C++ programing language to access the Oracle database.
You can now create SQL types mapped to existing Java classes to provide persistent storage for Java objects. Such SQL types are called SQL types of Language Java, or SQLJ types.