Re: rq23 def'n "Pattern Solution" wrong? (and more on BGP')

Enrico Franconi wrote on 02/28/2006 07:45:00 PM:

> On 1 Mar 2006, at 00:02, Pat Hayes wrote:
> >> - if we don't have BGP', the (abstract syntax representation of 
> >> the) answer set can not use bnodes which appear in the (abstract 
> >> syntax representation of the) query;
> >
> > That is true
> 
> That's enough for me.

Perhaps for you it is :-), but as someone who is striving to put a good 
faith effort to fully understand this debate to both make informed 
decisions in the future and to be able to educate SPARQL users and 
implementors within my organization, I'd like to ask you, Enrico, to 
address the full response that Pat made rather than to take these three 
words out of context. 

In particular, if I understand Pat correctly (please correct me if I do 
not), then he is stating that BGP' enables an ability that has never been 
discussed by the DAWG (presumably that does not have approved use cases or 
requirements driving it?) and also an ability for which no work has been 
done to fully enable due to other factors. Specifically, Pat observes that 
the SPARQL result document explicitly scopes bnode IDs to that document, 
and so there is no current mechanism by which an answer document could (in 
the concrete syntax) refer to bnodes mentioned in the query. (Pat writes: 
"it would involve having partially overlapping bnode scopes between the 
query and answer documents")

Could you please spare a few sentences (or a pointer to an earlier message 
if you feel this has already been addressed) that addresses these two 
points?

many thanks,
Lee

Received on Wednesday, 1 March 2006 13:47:10 UTC