Re: Requirement: queries written as RDF

On Sun, Apr 04, 2004 at 09:23:14AM -0700, Howard Katz wrote:
> 
> I'd be interested in hearing the use case for RDF/XML-encoded queries. Is it
> primarily driven by a need for machine-processing, or is there a vocal
> "human" component as well? For what it's worth, the XQuery group, using MAY
> and MUST terminology in their requirements document [1], noted that :
> 
>    o The XML Query Language MAY have more than one syntax binding
>    o The XML Query Language MUST be convenient for humans to read and write,
> and
>    o One query language syntax MUST be expressed in XML in a way that
> reflects the underlying structure of the query.
> 
> 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?

> [1] http://www.w3.org/TR/xquery-requirements/#N101C5
> 
> > -----Original Message-----
> > From: public-rdf-dawg-request@w3.org
> > [mailto:public-rdf-dawg-request@w3.org]On Behalf Of Rob Shearer
> > Sent: Friday, April 02, 2004 10:00 AM
> > To: Patrick Stickler
> > Cc: public-rdf-dawg@w3.org
> > Subject: RE: Requirement: queries written as RDF
> >
> >
> >
> > Just because some other language has a particular attribute is no
> > argument that the attribute should be a requirement of this group, nor
> > is the fact that several postings have taken that attribute as an
> > assumption.
> >
> > I need help understanding just *why* encoding queries as RDF is
> > desirable in its own right. Deciding on such an encoding is very very
> > limiting in terms of what our final recommendation could look like, and
> > I think we need some clear and concise arguments, supported by use
> > cases, for considering such a requirement, and we need to specify the
> > requirement clearly enough that we will know to what extent we've met
> > it.
> >
> > If RDF serialization falls out of our final design, then I don't see any
> > problem with that. But it's a very different situation from specifying
> > RDF serialization as a design goal.
> >
> > > -----Original Message-----
> > > From: Patrick Stickler [mailto:patrick.stickler@nokia.com]
> > > Sent: 01 April 2004 23:48
> > > To: Rob Shearer
> > > Cc: public-rdf-dawg@w3.org
> > > Subject: Re: Requirement: queries written as RDF
> > >
> > >
> > >
> > >
> > > On Apr 01, 2004, at 23:30, ext Rob Shearer wrote:
> > >
> > > >
> > > >
> > > > I'd like some clarification of just what we're trying to get at from
> > > > this requirement.
> > >
> > > As far as what I personally mean by this, c.f.
> > >
> > > http://sw.nokia.com/rdfq/RDFQ.html
> > >
> > > in particular the broad range of examples at the end.
> > >
> > > I'm in the process of implementing RDFQ. A very pre-alpha, partial
> > > version is accessible at http://sw.nokia.com/rdfq/
> > >
> > > (no need to point out its shortcomings, it's very preliminary...)
> > >
> > > >
> > > > Are we saying that we want queries to fit into the RDF/XML
> > > syntax? I'd
> > > > like clarification on just what users and use cases benefit
> > > from such a
> > > > syntax.
> > >
> > > C.f. my earlier postings to the WG and to the IG prior to
> > > Cannes about
> > > this
> > >
> > > http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JanMar
> > > /0056.html
> > > http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JanMar
> > > /0151.html
> > >
> > > http://lists.w3.org/Archives/Public/www-rdf-interest/2004Feb/0224.html
> > >
> > > > My experience is that forcing RDF/XML syntax just makes it damn
> > > > near impossible for humans to compose a document without
> > > lots of help
> > > > from tools.
> > >
> > > Have a look at the condensed Turtle/N3 query examples in the RDFQ
> > > documentation.
> > >
> > > I think you'll find that they are just as keyboard friendly
> > > and readable
> > > as Squish-like queries.
> > >
> > > I.e., in cases where users would need to manually type in queries
> > > (rather than use a query UI) they need not be forced to resort to
> > > RDF/XML, but can use other more user-friendly serializations of
> > > RDF -- while still having the queries remain full/pure RDF.
> > >
> > > > If queries are being generated automatically, most software
> > > > systems are pretty agnostic just what their output syntax is, so I
> > > > don't
> > > > see RDF representations as helping them much, either.
> > > >
> > > > Are we saying that we want queries to fit the RDF data
> > > model? If so, I
> > > > don't think it's met trivially, since just about anything can be
> > > > translated into RDF--that's the whole point of RDF.
> > >
> > > True, but that's alot more work for the query engine and each
> > > engine may interpret the non-RDF input in different ways and
> > > thus come up with different results.
> > >
> > > Having the query expressed from the start in RDF puts it within
> > > the scope of the RDF MT, which I think is a very useful thing
> > > to do.
> > >
> > > Have a look at the RDFQ materials and then say what you think
> > > about this requirement.
> > >
> > > Cheers,
> > >
> > > Patrick
> > >
> > > --
> > >
> > > Patrick Stickler
> > > Nokia, Finland
> > > patrick.stickler@nokia.com
> > >
> > >
> >

-- 
-eric

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Received on Wednesday, 7 April 2004 09:29:15 UTC