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At 02:19 PM 3/25/99 -0500, Gavin Thomas Nicol wrote: >I wouldn't bet my farm on that proposal. Folk at QL'98, both database >and IR, had serious issues with it. Frankly, I don't know of anything that has been proposed to the XML or web communities that hasn't found its critics. XQL has found both avid fans and strong critics. Since you make no specific technical claims here, it is hard to dismiss what you say with information, but perhaps I can make some broad statements that address what you are implying here. Both database and IR people made contact with me at QL'98, showing interest and appreciation, and we have been in active and enthusiastic correspondence ever since. XQL has been more widely implemented than any other XML query language (I just posted information on six implementations today), and it is closely related to XSL Patterns. The main criticism from database folks was that they wanted to see joins and transformations in XQL. Peter Fankhauser has proposed extensions to XQL for joins. Declarative transformations are, of course, very useful, but XSL can also be used for transformations. One of the big reasons for leaving joins and transformations out of the first version was to make implementation simple - which is why there are quite a few implementations of XQL. I suspect that there will be later versions of XQL that include at least joins; I'm less certain about declarative transformations, since XSL already exists and can do transformations, but I do really like declarative transformations. At least one IR person criticized XQL for doing too much, eg for having the parent/child relationship in addition to the ancestor/descendant relationship. This does, in fact, increase the complexity of implementation, but offers a distinction that I find important. The number of implementations of XQL shows that there's a fair amount of interest in it. People who have demonstrated it at trade shows send me email telling me how impressed people are - for instance, I have been getting email from Software AG, which is showing XQL at CeBIT this week and getting very enthusiastic responses. When I discuss XQL at trade shows, I get enthusiastic responses. So the fact that there are also critics doesn't bother me. If you want to implement a query language today, for reasonable effort, and you want to use a language that has been implemented in other software systems, I think XQL is a very good choice. There will be a W3C XML Query Language Activity, and it will develop its own query language, and nobody can say how similar or different it will be to any existing query language for XML. I'm sure there will be a lot of interesting and creative work done by the bright people who will be involved in that group - if you can afford to wait a year to implement a query language, then by all means wait for that language to be developed. Jonathan jonathan@t... Texcel Research http://www.texcel.no xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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