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Re: Datatypes (ISSUE-48)

From: Nuno Lopes <nuno.lopes@deri.org>
Date: Wed, 10 Aug 2011 11:48:14 +0100
Cc: Nuno Lopes <nuno.lopes@deri.org>, Richard Cyganiak <richard@cyganiak.de>, W3C RDB2RDF <public-rdb2rdf-wg@w3.org>
Message-Id: <A66EDCC0-5151-4BC7-83F1-4601A52587CE@deri.org>
To: Ivan Herman <ivan.herman@gmail.com>
Hello Ivan,

The "facets used" indicate how the SQL spec handles restricting the (generally) broader lexical space of the XSD datatypes.  It seems that if we want to used this exact mapping we'd need to take the OWL 2 approach.  Using RDF means a more "relaxed" approach to representing the datatypes (which might be ok, I'm not advocating the use of OWL 2 datatypes). 

regards,
--
Nuno Lopes



On 10 Aug 2011, at 07:37, Ivan Herman wrote:

> I have a clarification question. What is the role, in here, of the 'facets used' column? If we stick to XSD datatypes, then those facets cannot be used in terms of RDF. We could, of course, use OWL 2 to define new datatypes (OWL 2 has the notion of facets and one can define new datatypes derived from XSD datatypes using those); is this the intention?
> 
> Personally, though using OWL 2 might be very elegant, I am not sure that practical implementations would make a lot of good use to it. OWL 2 Datatype reasonings are part of OWL reasoners, but I am not sure there are tools that would do Datatype reasoning _only_. Ie, the practical usage might be limited. But, who knows, it may be a good approach after all...
> 
> Ivan
> 
> 
> 
> On Aug 9, 2011, at 20:03 , Richard Cyganiak wrote:
> 
>> Hi Nuno,
>> 
>> I had another look at the wiki page:
>> http://www.w3.org/2001/sw/rdb2rdf/wiki/Mapping_SQL_datatypes_to_XML_Schema_datatypes
>> 
>> Ok, this answers what we ought to do with user-defined and constructed types.
>> 
>> There are still a couple of questions open from here:
>> http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Aug/0017.html
>> 
>> Maybe you could comment on these?
>> 
>> Cheers,
>> Richard
> 
> 
> ----
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
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> FOAF: http://www.ivan-herman.net/foaf.rdf
> 
> 
> 
> 
> 
Received on Wednesday, 10 August 2011 10:48:53 UTC

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