Typical Back-Office Application Scenario
Modern operating systems architecture and three-tier design has led to modularization in back-office applications. The same features that made it easy to upgrade business rules and database systems make it easy to modify interfaces between components without affecting the stability of the system as a whole.
Abstract data access methods, such as the Open Database Connectivity (ODBC) interface, have allowed client applications to divorce themselves from the actual database system itself. Figure 9.1 shows a typical modern back-office application involving a relational database and an application server.
Figure 9.1. Typical back-office application.
This modularity provides several points where XML-aware components can be inserted. The following sections outline various ways that XML support can be added to an existing system.