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Re: Plain literals and xsd:string

From: Steve Harris <steve.harris@garlik.com>
Date: Wed, 20 Apr 2011 18:43:01 +0100
Cc: public-rdf-dawg@w3.org
Message-Id: <27B7C806-7C12-4AB9-BF77-9B29F406583A@garlik.com>
To: Andy Seaborne <andy.seaborne@epimorphics.com>
On 2011-04-20, at 09:47, Andy Seaborne wrote:
> 
> On 19/04/11 23:17, Steve Harris wrote:
>> Hi all,
>> 
>> The RDF WG intends to recommend that xsd:strings be silently
>> converted to RDF plain literals internally. See Resolution 1 in
>> http://www.w3.org/2011/rdf-wg/meeting/2011-04-13.
>> 
>> This would have some impact on SPARQL deployments, as we go to some
>> lengths in a few places to preserve the differences. I'm not sure it
>> should necessarily affect the wording of any of the SPARQL texts, but
>> it's probably worth bearing in mind. It could be that we can simplify
>> some wording, but we should take care not to become dependent on a
>> new RDF rec. for publication.
>> 
>> - Steve
>> 
> 
> What should update do?
> 
> INSERT DATA { :s :p "foo"^^xsd:string }

The wording of the RDF-WG resolution suggests that systems should silently convert to plain literal internally.

> It affects query.  BGP matching is simple entailment.
> The wording must change there surely?

Perhaps...

> Either that or
> 
> SELECT * { ?s ?p "foo"^^xsd:string }
> 
> will stop matching on data now converted to "foo" without a software change to the query engine.

Right, true.

I don't have a clear feeling on how we should/could/ought to proceed. Is a decision from another WG enough new information for us to reopen that discussion?

> Existing databases + new software will see a change.
> 
> In my experience, it is OWL tools that will be affected as they like to use xsd:string in RDF for ontologies.

I've seen xsd:string in a couple of other places too, but it's fairly uncommon.

- Steve

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Received on Wednesday, 20 April 2011 17:43:30 GMT

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