C, which is responsible for its development. Several companies, including Microsoft, IBM, MarkLogic and Saxonica, have moved to commercialize XQuery with diverse tools aimed at easing its implementation.
Robie said there are more than 45 commercial XQuery implementations, which should hardly come as a surprise. Even longtime backers of relational database technology have conceded that XQuery brings a powerful new tool to the XML data-management arena.
In media coverage of the XML 2006 conference held in Boston in December, Oracle's Principal Architect Roger Bamford was quoted as saying XQuery could allow speedy revisions within databases that would otherwise be slow to adjust to the introduction of new data.
Programming Made Simple
XQuery is designed to answer fundamental questions about the management of data, Robie explained. "How do you find stuff in XML? How do you combine stuff from different sources? How do you create new results and new structures? Those are all primitives in XQuery -- things XQuery does naturally."
This could be good news for government IT workers, many of whom have come to rely on XML-driven data systems, which tend to offer easier and more legible access to information than their relational predecessors.
For those IT professionals, XQuery is a labor-saving mechanism. "It processes XML efficiently, by which I mean efficiently for the programmer, because the programmer doesn't have to spend all his time explaining things to the system," Robie said. "The system already understands what XML is, so the programmer writes a lot less code."
This is a big step forward from the relational model. "If you are a programmer working in SQL, and someone has a new data source for you," Robie said, "you are going to crack open some manuals and start studying."
In XQuery, the language assumes everything is XML and leaps forward to execute.
Users say it's relatively easy to acquire a fluency in XQuery basics. Harvey turned to the language to develop an interactive dictionary, and recalls boarding a train not knowing a thing about it. "By the time I took the train to New York, had a meeting and took the train back," she said, "I had a working product that I could give to my client. If you are familiar with XML and XML technologies, it is not that hard to work with."
But even those programmers with significant XML deployments already in place will need to proceed with some caution, as the worlds of SQL and XQuery still overlap. "You still need the right tool for the right job," said Oracle's Hardie. "There may be very clear cases for one and very clear cases for the other, but that will never stop some people from trying to drive a screw with a hammer."
Though XML and XQuery technologies are on the rise, the relational database world is far from over. "We have at least a decade ahead of us," Robie said. "You've got so much expertise, so many people who know what to do with relational databases -- and relational databases still are very efficient at what they do."