3.1 Overview

The new Internet computing environment has brought new kinds of data to a huge number of users across the globe. Multimedia data types such as images, maps, video clips, and audio clips were once rarely seen outside of specialty software. Today, many web-based applications require their database servers to manage such data. Other software solutions need to store data dealing with financial instruments, engineering diagrams, or molecular structures. An increasingly large number of database applications demand content-rich data types and associated content-specific business logic.

With the addition of object-relational extensions, the Oracle8 i Server (Oracle 1999b, 1999d) can be enhanced by developers to create their own application-domain-specific data types. For example, one can create new data types representing customers, financial portfolios, photographs, or telephone networks and thus ensure that database programs deal with the same level of abstraction as their corresponding application domain. In many cases, it is desirable to integrate these new domain types as closely as possible with the server so they are treated at par with the built-in types such as NUMBER or VARCHAR. With such integration, the database server can be readily extended for new domains.

Oracle8 i gives application developers greater control over user-defined data types, not only by enabling the capture of domain logic and processes associated with the data, but also by providing control over the manner in which the server stores, retrieves, or interprets this data. The Oracle8 i