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