This chapter presented the basic technologies required to enable a relational database with XML to cover the current main scenarios of exporting and importing structured XML data. Based on SQL Server 2000's XML support, it gave an overview of the different building blocks such as HTTP and SOAP access, queryable and updateable XML views, rowset views over XML, and XML serialization of relational results. Rowset views over XML and the XML serialization of relational results can be characterized as providing XML support for users feeling comfortable in the context of the relational world, whereas the XML views provide XML-based access to the database for people more familiar with XML.
The next generation of relational systems will not stop at this level though. Besides working on standardizing the server-side aspects of XML generation (Eisenberg and Melton 2001), they will also add support to deal with native XML documents in the form of an XML data type. Besides the logical next step to provide better support for the semi-structured and marked-up uses of XML, they will be providing support for the increased expectation that more and more of the XML messages and documents will have to be stored and queried in their native form. Thus, XQuery support both over the XML views described in this chapter and the XML data type will be another important capability of the second phase of XML support in relational database systems.