XQuery: The XML Query Language

book cover

by Michael Brundage

Published: Addison-Wesley Professional, 2004

505 pp., list price US$59.99

ISBN: 0-321-16581-0


Send in your questions! xquery@qbrundage.com

Q: Which version of XQuery is your book based on?

A:The latest drafts at the time we went to press were the November 12, 2003 Last Call drafts. As XQuery continues to evolve, I'll post updates here.

Q: Why should I buy your book when XQuery isn't finished yet?

A:My book is based on the same Last Call drafts used by several XQuery implementations. If you're using one of those implementations, then this is ideal. Even if you're not, this is the most stable version of XQuery that will be available until at least late 2004 (and possibly longer). If you're using XQuery now, there's no reason to wait.

Q: How stable is XQuery? Can I already deploy it in my applications?

A:The short answer is: XQuery is still under construction. Starting XQuery development is possible now, but deployment is only feasible if you're willing and able to absorb the cost of upcoming changes to XQuery and its implementations.

The long answer goes like this: XQuery is a new standard still under development. Consequently, all implementations of it are still evolving, and none are yet mature or especially stable. Typically, W3C Last Call drafts undergo relatively few major changes between then and Proposed Recommendataion, and fewer still before achieving final Recommendation status. XQuery has reached the "Last Call" stage, but will likely undergo more than the usual number of changes between now and finalization.

Although there are already a few deployed projects based on earlier drafts of XQuery (such as Apple's Sherlock 3), all of them will require updating (with breaking changes) to be compatible with the final XQuery standard.