XQuery from the Experts: A Guide to the W3C XML Query Language

Implementation Concepts

Generally, details of implementation are hidden within the database or middleware that implements the XML view of relational data. Nevertheless, it is valuable to understand the basic approaches in order to gain insight into performance or for debugging. A thorough discussion of implementing the different kinds of applications introduced in the second section, using different XML representations and different mapping techniques, is beyond the scope of this chapter. Our aim in this section is to outline the basic requirements for implementation. We begin with the simple application type of emitting XML documents, which allows us to introduce several implementation strategies for composed techniques—most important, the varieties ...