Delivering Targeted Information

Before XML, complex Web sites that deliver targeted information to users were built using scripting and RDBMS technology. If a company wanted to host an online monthly newsletter, for instance, a programmer developed a database schema to contain the articles, advertisements, and editorial information. Then he developed a Web application that could display data from the database and possibly allow users to dynamically update the database. If the structure of the newsletter needed to change, the underlying schema had to be modified, and any scripts dependent on the schema had to be fixed as well.

This programmer/DBA intensive approach created several problems:

• Systems either lacked flexibility or were extremely complex.

• Programmers were forced to develop custom caching systems to improve performance as user loads increased.

• Database systems are inefficient for storing and retrieving static content.

XML combined with XSLT offers most of the power of script/database solutions with a fraction of the complexity and overhead. Rather than involving a programmer in structural changes, a user with a WYSIWYG XML editor can make any desired changes to the newsletter document type definition. Then a Web designer can update the XSLT transformation scripts so that the new content is correctly displayed. As a side benefit, the entire text of the newsletter is available in XML format for other applications (such as formatting for e-mail or print distribution).