- From: Graham Klyne <GK@NineByNine.org>
- Date: Fri, 29 Nov 2002 17:15:12 +0000
- To: "Danny Ayers" <danny666@virgilio.it>
- Cc: <jeffzhang726@yahoo.com.cn>, <www-rdf-interest@w3.org>
Yes. I think many applications would eliminate the duplicates, but strictly speaking they're not wrong (according to RDF) if they don't. #g -- At 04:13 PM 11/29/02 +0100, Danny Ayers wrote: > >Dear Graham, > > I mean the first example > > ex:foo ex:property ex:bar . > >and > > ex:foo ex:property ex:bar . > > ex:foo ex:property ex:bar . > > > >Our team is developping an rdf engine which has an API as its part. > >When we discuss about the operation of adding a statement to a > >graph, we are puzzled > >about whether a statement should be added to the graph if there is > >already a same > >statement in the graph. As to the rule of merging graphs, it seems > >the same statement should be added to the graph. But we can not > >find any real world example in which multiple copies of statements > >make different meanings with single statement. Is there any example? > >(not Graham, but still) > >let me try...I hope I've got this right... > >if we assert a couple of statements > >http://example/x dc:creator Jeff >http://example/x dc:creator Jeff > >then ask the question, > >http://example/x dc:creator ? > >then we should get the answer > >http://example/x dc:creator Jeff > >or > >http://example/x dc:creator Jeff >http://example/x dc:creator Jeff > >or even > >http://example/x dc:creator Jeff >http://example/x dc:creator Jeff >http://example/x dc:creator Jeff > >- they're all true > >if had asserted instead > >http://example/x dc:creator Jeff >http://example/x dc:creator Ora > >the answer could have been > >http://example/x dc:creator Jeff >http://example/x dc:creator Ora > >or > >http://example/x dc:creator Ora >http://example/x dc:creator Jeff >http://example/x dc:creator Jeff > >or other variations, depending on the app. In practice I suppose we'd avoid >having the query just return a 'null' statement, even though that would in >effect be true too. So in an app I would be tempted to go for the simplest >solution, i.e. merge two identical statements into one. > >Cheers, >Danny. ------------------- Graham Klyne <GK@NineByNine.org>
Received on Sunday, 1 December 2002 05:08:48 UTC