- From: Paul Gearon <pag@tucanatech.com>
- Date: Sat, 9 Oct 2004 16:32:26 +1000
- To: www-rdf-interest@w3.org
On 07/10/2004, at 7:50 AM, Charles McCathieNevile wrote: > On Wed, 6 Oct 2004, Jan Algermissen wrote: > >> this is likely to be a silly question, but I seem to be unable to >> parse >> the anser from the RDF Recommendations. >> >> "An RDF graph, or simply a graph, is a set of RDF triples." >> (from RDF Semantics, 0.3 "Graph Definitions") >> >> Since the graph is a set it does not contain duplicate triples, yes? > > I recall a discussion on this topic recently. I believe that someone > who > knows the spec better than I do said the formal definition doesn't > prohibit > redundant triples, so a conformant program would not necessarily delete > them... I can't comment on the formal spec on this specific point, as I haven't checked it [1], but I think it worth mentioning two related points. First, most (all?) RDF databases do not store redundant statements. I know that Kowari certainly doesn't. Second, collections use a cons list, which seem especially designed to avoid creating duplicate statements if the same item is included twice. Having worked with these for a while, I can't think of any reason for this construction except that RDF is trying to avoid duplicate statements in an environment which does not permit them. So I would just assume that duplicate statements are dropped. If you're concerned, then check the system you're using before going proceeding too far. [1] I'm going to be spending an hour or two looking for this now, aren't I? :-( Regards, Paul Gearon Software Engineer Tucana Technologies http://www.tucanatech.com Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam. (Translation from latin: "I have a catapult. Give me all the money, or I will fling an enormous rock at your head.")
Received on Saturday, 9 October 2004 06:33:07 UTC