- From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
- Date: Wed, 22 Dec 2004 18:41:56 +0000
- To: DAWG public list <public-rdf-dawg@w3.org>
On Wed, Dec 22, 2004 at 06:35:54PM +0000, Andy Seaborne wrote: > >>>heuristics based nataural language software, so hte query (in DAWG speak) > >>>was: > >>> > >>> SELECT ?id ?title > >>> WHERE SOURCE ?src (?id dc:title ?title) > >>> (?src dc:creator ?creator) > >>> AND ?creator !~ /^Armadillo/ > >>> > >>>assuming a direct relation between the SOURCE node and the document URI, > >>>and > >>> > >>> SELECT ?id ?title > >>> WHERE SOURCE ?src (?id dc:title ?title) > >>> (?src dawg:source ?doc) > >>> (?doc dc:creator ?creator) > >>> AND ?creator !~ /^Armadillo/ > >>> > >>>if not. s/dawg:source/dc:source/ if you prefer > >> > >>Both queries are legal. Just depends what you decide to put in the > >>default KB. You can model your provenance how you like. > >> > >>In either design, ?src is a URI (otherwise you can't put it in a graph) - > >>bNodes also work apart from GRAPH declarations (which 3Store wouldn't > >>use) but ?src as a graph does not. > >> > >>Collapsing dawg:source (i.e. design 1) is a matter of do you want to > >>record other information gainst ?doc that is not true of ?src. As ever, > >>a more detailed modelling gets inconvenient in general use. returning > >>?src (some pre-read-in-doc) URI is not going to be what apps usually > >>want. Unless they are the data maintenance app, of course! > > > > > >Yes, exactly. The problem with collapsing is that it rules out that class > >of data-maintainance task. I agree its somewhat inconvient though, as the > >2 queries show. > > > >In defense of the dawg:source style, systems that dont care about > >historical provenance can just assert (<uri> dawg:source <uri>) and get on > >with it. > > > >I could live with a collapsed form though, > > You don't have to! You-the-DB-designer can choose. It isn't a WG > decision. That's what I meant by both are legal. OK, well that will require some very carefully worded specs and testcases. - Steve
Received on Wednesday, 22 December 2004 18:42:00 UTC