- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Wed, 19 Oct 2011 14:32:52 +0100
- To: public-rdf-wg@w3.org
On 18/10/11 16:25, Antoine Zimmermann wrote: > Dear all, > > > I was overloaded with other things and haven't participated in the > recent discussions around graph and dataset semantics but I am now > catching up and these are some thoughts I have after reading all that > was said. I'd like to get your opinion on this. > > These are some things I expect regarding the semantics of datasets: > 1. They should not impact the semantics of RDF; > 2. There is no single fit-for-all semantics of datasets so the semantics > must be flexible to accomodate use cases and existing implementations; > 3. There should exist a way to tell the world what specific semantics > one application is using. > > Item 1 implies that the semantics of datasets are distinct from the > semantics of RDF. > Item 2 implies that different conformant applications may entail > different things. Yet, there should be common requirements to make a > semantics "conformant". > Item 3 is rather open but I am thinking of something like a description > of a dataset that says, e.g., "bnodes are locally scoped" or (following > Sandro's proposal) "graph labels are used to RDF-denote the graph > containers" or "the default graph is the union of the named graphs" or > "the default graph represents shared knowledge, valid in all named > graphs", etc... All these statements say something about the semantics > of datasets that is used in a system. > > Regarding the minimal requirements for a semantics of datasets, there is > already a proposal [1]. I updated it to make it clearer. That proposal > addresses many of the issues that Richard puts forward in a recent email > [2]. In particular, it says that what is "true in a graph" (or, in a > context) is not necessarily true in a different graph (or context). This > minimal semantics does not provide any means of talking about an RDF > Graph. This should be addressed by the mechanism that I envision in Item > 3 above. > > > [1] Semantics (in TF-Graphs/RDF-Datasets-Proposal). > http://www.w3.org/2011/rdf-wg/wiki/TF-Graphs/RDF-Datasets-Proposal#Semantics [1] seems reasonable to me. Andy > > [2] Datasets and contextual/temporal semantics. > http://lists.w3.org/Archives/Public/public-rdf-wg/2011Oct/0212.html
Received on Wednesday, 19 October 2011 13:33:24 UTC