Oracle PL/SQL Programming, Third Edition

Object Views

Although Oracle’s object extensions offer PL/SQL programmers rich possibilities for the design of new systems, it’s unlikely that you will want to completely reengineer your existing systems to use objects. In part to allow established applications to take advantage of the new object features over time, Oracle provides object views. This feature offers several unique advantages:

“Object-ification” of remote data

It’s not yet possible in Oracle9i to use the object tables and physical REFs across a distributed database, but you can create object views and virtual REFs that cast remote relational data as objects.

Virtual denormalization

In a relational database or even an object-relational database, you will usually find relationships modeled in only one direction. For example, a book has some number of subjects. With an object view, it’s easy to associate a column that provides the inverse mapping; for example, a subject object could include a collection of REFs that point to all of the books in that subject.

Efficiency of object access

In Oracle Call Interface (OCI) applications, object programming constructs provide for the convenient retrieval, caching, and updating of object data. By reducing trips between application and database server, these programming facilities may provide performance improvements, with the added benefit that application code can be more succinct.

Greater flexibility to change the object model

Although Oracle9i has tremendous abilities in the ...