For this last chapter in the book, we wanted to take a step back – actually, to take several giant leaps back – and consider what “querying XML” is intended to achieve. In the bigger picture, the technologies we have discussed for querying XML, such as SQL/XML and XQuery, provide some useful infrastructure to achieve universal, intelligent search over all information. Most people don’t care in the slightest whether the underlying technology to achieve this involves SQL or XQuery or XML – all they care about is finding stuff.
We break “finding stuff” down into the various kinds of stuff that you might want to find. We start with structured data, which is the simplest and, currently, the most useful ...