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Re: Requirement: queries written as RDF

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Thu, 8 Apr 2004 09:38:28 +0300
Message-Id: <584A6ECE-8927-11D8-950F-000A95EAFCEA@nokia.com>
Cc: <public-rdf-dawg@w3.org>, "Rob Shearer" <Rob.Shearer@networkinference.com>, "Eric Prud'hommeaux" <eric@w3.org>
To: "ext Howard Katz" <howardk@fatdog.com>


On Apr 08, 2004, at 08:07, ext Howard Katz wrote:

>
>
> I got several responses back from members of the Query wg on the 
> XQueryX
> question. I particularly liked this one. I don't know if it'll shed any
> light on our own issues, but it's delightfully clear and succinct. The
> author prefers to remain anonymous.

Very interesting.

I'm sympathetic to the view reflected in one of Eric's recent posts
that we shouldn't presume that everything relevant to the design or
process of design of XQuery(X) is relevant to DAWG, but I still think
there are some useful insights here.

>
> In response to a question on why XQueryX:
>
>> (1) An XML-based syntax was considered easier for machines to
>> generate and exchange than a human-oriented syntax that would
>> require some sophisticated parsing.

A nice benefit of Turtle is that is provides both keyboard-friendly
(i.e. human-oriented) syntax yet full RDF precision.

In a sense, it allows us to "have our cake and eat it too"...

>> (2) If queries are represented in XML they can be treated as data
>> and you can run XQueries over a collection of XQueries.

Also relevant to queries expressed in RDF.

Also, one can reason over queries expressed in RDF, not merely
search a knowledge base containing such queries.

>> (3) Since XML is known to be an answer to all questions, it must be
>> an answer to the question "What would be a good format for expressing
>> queries over XML data"?

;-)

I think it's important to stress that adopting queries expressed
as RDF does *not* necesarily mean requiring that all queries be
encoded as RDF/XML (though, obviously, RDF/XML would be supported
automatically).

It's the RDF model we want to take advantage of here, not a
particular serialization.

>>>> I certainly agree with the sentiments of the second, "human 
>>>> readable"
>>>> requirement. Interestingly enough, the third, "XML" requirement
>>> has been the
>>>> one that's caused the group the most difficulty to my
>>> knowledge, and at the
>>>> moment conformance with this requirement has been downgraded to
>>> optional. I
>>>> don't know what the major issues have been, but it might be
>>> interesting to
>>>> know, if only for the sake of curiosity.
>>>
>>> Can we go beyond the meta-lesson of "that may be hard. it's been hard
>>> in XQuery" to some of the particular problems that requirement caused
>>> the XQuery WG? Also, was this requirement born of some compelling use
>>> cases, or a general notion that it's good practice to express 
>>> anything
>>> in XML?
>>
>> I wasn't trying to impart a particular lesson. My intention, not 
>> knowing
>> what DAWG members know or don't know about it, was simply to
>> provide data on
>> the experience of the Query wg in the event that might prove useful 
>> to the
>> group. In response to your questions, I've asked several members of 
>> the wg
>> about their XQueryX experience. If they see fit to pass that on
>> to me, I'll
>> be happy to share it with the group.

I, for one, have found your input very useful.

Cheers,

Patrick


>>
>> Howard
>>
>
>

--

Patrick Stickler
Nokia, Finland
patrick.stickler@nokia.com
Received on Thursday, 8 April 2004 02:42:10 GMT

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