W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > July to September 2006

Re: ACTION item(s): definition(s) and an algorithm for postprocessing minimization

From: Steve Harris <steve.harris@garlik.com>
Date: Fri, 25 Aug 2006 08:15:33 +0100
Message-Id: <4F1AA08F-157A-4478-819F-55E43E7834B7@garlik.com>
Cc: Bijan Parsia <bparsia@cs.man.ac.uk>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
To: Pat Hayes <phayes@ihmc.us>


On 24 Aug 2006, at 17:52, Pat Hayes wrote:
>>
>>>> So, first qualification: These algorithms are only minimizing  
>>>> with respect to BNodes. You have to plug in your own account of  
>>>> literals.  I use "row" for "answer" avoid confusion:
>>>> DEFINITION 1: Answer graph template
>>>> 	Let A be an answer set and Avar be the set of column headings  
>>>> of A.
>>>> 	The answer graph template of A is the set of triple patterns,  
>>>> such  that:
>>>> 		{tp | _:row ('http://var.org/#" ++ var) var. & var \in Avar}
>>>                                                         ^^^
>>> value?
>>
>> I just needed a random URI prefix. Substitute any you like.
>
> We did once consider a proposal to have a special 'anonymous'  
> prefix, basically an IRI space solely for skolem names, as part of  
> the spec. That idea kind of died, I think (?) because it was felt  
> to be artificial and not in the IRI spirit of rock-solid eternal  
> universal identifiers that retain their meaning throughout the  
> known universe, but it might be worth reconsidering it. There are  
> emails about this in the archive somewhere but I confess I can't  
> actually find them now.

For the record, JXT (my RDF store that runs on clusters) uses the  
bnode: URI space to skolemise bnodes reported in SPARQL results, eg.  
<bnode>foo</bnode> can be referred to in subsequent queries as the  
URI <bnode:foo>.

I was going to use <_:foo> but I had some problems related to parsing  
that.

- Steve
Received on Friday, 25 August 2006 07:15:12 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:27 GMT