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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


--

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

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