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RE: XQuery types was Re: Yet another plea for XUpd

• To: "Dare Obasanjo" <dareo@m...>,<xml-dev@l...>
• Subject: RE: XQuery types was Re: Yet another plea for XUpdate...
• From: Jonathan Robie <jonathan.robie@d...>
• Date: Tue, 07 May 2002 11:51:07 -0700
• In-reply-to: <8BD7226E07DDFF49AF5EF4030ACE0B7E05573D1E@r...>

At 11:03 AM 5/7/2002 -0700, Dare Obasanjo wrote:
>I don't understand why you continue to miss my point. My original 
>assertion which started this thread was that the XQuery WG was and is 
>incorrect in stating that a static type system is necessary to add DML 
>semantics to XQuery.

I never said it was necessary, but I do believe it to be desirable.

If your updates would create invalid data, they should fail dynamically. 
But if they are going to fail dynamically, and a static type system can 
tell me that, I would rather see the error today, *before* I ship my new 
query library to a thousand users whose data may be different from my test 
cases.

>The fact of the matter is that regardless of all the complexity you place 
>on implementors (which will probably lead to a "Can anybody implement 
>XQuery?" thread on XML-DEV in 12 months) the fact of the matter is that 
>DML will still require post-update validation in a wide range of cases.

In fact, I think it reasonably likely that many of the early 
implementations of XQuery will not implement the static type system, and I 
also think it likely that the XML Query Working Group will make static 
typing optional for implementations. Personally, I expect reasonably good 
support for the dynamic typing.

I agree with you that implementability is an important criterion. Who can 
implement XQuery? Well....

Cognetic Systems: http://www.cogneticsystems.com/xquery/xquery.html
Enosys Markets: http://www.enosysmarkets.com/products/xq.html
Fatdog: http://www.fatdog.com/
Ipedo's XML Database v3.0: http://www.ipedo.com
IPSI-XQ: http://xml.ipsi.fhg.de/xquerydemo
Lucent: http://db.bell-labs.com/galax/
Microsoft: http://xqueryservices.com
OpenLink Software (Virtuoso Universal Server): 
http://demo.openlinksw.com:8890/xqdemo
Oracle: http://otn.oracle.com/tech/xml/xmldb/htdocs/querying_xml
Qexo (Kawa-Query): http://www.qexo.org/
Software AG: http://www.softwareag.com/developer/downloads/default.htm
Sourceforge's Kweelt: http://kweelt.sourceforge.net/. Open-source.
SourceForge's XQuench: http://xquench.sourceforge.net/. Open-source.
X-Hive: http://www.x-hive.com/xquery
XML Global: http://www.xmlglobal.com

>  Secondly, if XQuery wasn't so wedded to W3C XML Schema, the W3C wouldn't 
> be forcing users of XQuery to also become users of W3C XML Schema but 
> instead would allow them to use whatever XML schema technology they liked 
> including DTDs and RELAX NG.

XQuery will have explicit support for DTDs, well formed XML, and schemas. I 
think it will probably be possible, but challenging, to define a RELAX NG 
mapping.

For all of these, I do think that using the XML Schema built-in types is a 
strength, not a weakness. You really do want to know what an integer is.

Jonathan

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    • From: "Dare Obasanjo" <dareo@m...>

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