XML query specs closer to completion

Two World Wide Web Consortium (W3C) groups have released 10 working drafts of specifications intended to allow collections of...

Two World Wide Web Consortium (W3C) groups have released 10 working drafts of specifications intended to allow collections of XML files on the web to be queried like databases.

The drafts address the problem of locating and retrieving information from documents compliant with XML, a protocol for describing the type of data contained in a structured document.

The W3C's XML Query working group task will be to solve this problem, with the assistance of the XSL (Extensible Stylesheet Language) working group.

The core of the XML Query group's efforts is the creation of XQuery, a language for searching XML documents. Among the 10 drafts is an updated version of the XQuery 1.0 specification, as well as an updated version of the closely related draft of XPath 2.0, a language for addressing parts of XML documents.

When XQuery is complete, it will be supported by products such as databases and content management applications. Backers include Microsoft, IBM, BEA Systems and Oracle.

Two of the drafts, XQuery 1.0 and XPath 2.0 Data Model and XQuery 1.0 and XPath 2.0 Functions and Operators have been bumped to "last call" status, which means the specifications are considered essentially complete and ready for public review.

The two drafts' last-call review period will end on 30 June, after which needed changes will be made and the documents will be eligible for "candidate recommendation" status, according to W3C spokeswoman Janet Daly.

Elevating those two specifications will clear the way for the XQuery language proposal, which has been under development for several years, to proceed to final review stages.

Several steps remain before finalisation once a specification advances to candidate recommendation status, but the XQuery-related proposals are likely to move quickly along the recommendation track because test implementations are already underway, leading to early discovery of potential problems, according to Daly.

Because XQuery needs to interoperate smoothly with a number of other protocols, its creators have been focused on testing it widely during the development process, she said.

"I think it's possible to see things mature by the end of 2003," Daly said. "I think everyone would like to see that, and I wouldn't rule it out."

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