Using XML and Object Databases
If you have existing data, this architecture is also a great way to use XML to take advantage of it. Your existing data is protected from direct Internet access and data from multiple existing sources can be mapped to the object database.
The object model used by the object database is a perfect match for XML. For an example of an XML model, see complex data.
You will also find that many ODBMS vendors provide XML capabilities.
XML may be presented at the application level above the object database and used by the web or application server. XML may also be presented above the web or application server. It depends on the products you might use.
Also see the following sets of articles:
More on the general topic: Architecture with Existing Data Sources