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Re: RDFQ - RDF Queries in RDF

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Thu, 8 Apr 2004 09:34:28 +0300
Message-Id: <C8F845AA-8926-11D8-950F-000A95EAFCEA@nokia.com>
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
To: "ext Eric Prud'hommeaux" <eric@w3.org>

On Apr 07, 2004, at 15:56, ext Eric Prud'hommeaux wrote:

>>> The useful difference being if one
>>> must ask a combinatorial factor of all the disjunction optoins. For
>>> reference, see FatAnnotationQuery (EP-4) [1] where the query asks for
>>> two properties that may be dc1.0 or 1.1. This seems like it would
>>> require four queries in RDFQ.
>> I think the issue here is that RDFQ may not provide for quite
>> as tight a compression as other forms of expression, but one
>> then has to weigh how often/widely complex boolean expressions
>> will be needed/used.
> Can one express queries in RDFQ where an arbitrary subset of the terms
> in the graph are logical disjuctions according to a popular definition
> of "disjuction" [2] ? I don't mean "Can you use a query compiler to
> caluculate the set of queries that will express the disjunction?"

Perhaps not as presently defined. But being an RDF vocabulary, it would
probably be straightforward to add.

> When characterizing the expressiveness of the query languages, we must
> be honest and precise or there's no point in the exercise.

I agree. But I found some of your characterizations to have the bar
set higher than it perhaps should be, i.e. "if cannot lift 200kg
then conclude cannot lift any weight".



Patrick Stickler
Nokia, Finland
Received on Thursday, 8 April 2004 02:42:02 UTC

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