Re: Proposal to drop disjunction requirement

On Fri, Oct 01, 2004 at 06:17:16PM +0100, Steve Harris wrote:

> conjunctive ones, but it explodes the number of queries needed
> dramatically.

In cases where the implementation strategy is based on RDBMS/SQL or in
every case? I genuinely don't know.

> In any case, I'm not convinced that users generally think in terms of
> graph level disjunction, as I said I've not had requests for it. 

IIRC, Network Inference gets this a lot from its users and that's how
2.13 ended up in UC&R.

> SQL has
> no equivalent syntaxic form to graph disjunction

Hmm, well, that's of only limited applicability here, IMO. But YYMV
and clearly does. :>

> > We have 2.13 and 3.13 in UC&R that imply disjunction in SPARQL. I
> > haven't heard enough to disregard that.
> 
> 2.13 can be answered just as well with []'s, and 2.13 is the justification
> for 3.13.

Well, as you say, we don't have a proof that optionals can satisfy
2.13 in every case. We do have evidence that doing so in common cases
puts a pretty high burden on users. Some of those
disjunction-via-optional examples are a bit hairy. I can't imagine
ordinary folks writing them.

Anyway, I've said my piece about this. Thanks for the response.

Kendall

Received on Friday, 1 October 2004 17:25:05 UTC