- From: Axel Polleres <axel.polleres@deri.org>
- Date: Mon, 23 Nov 2009 15:49:18 +0100
- To: SPARQL Working Group <public-rdf-dawg@w3.org>
FYI, some conversation with Marcelo Arenas from the RDB2RDF working group which I share with his permission... Axel Begin forwarded message: > From: Axel Polleres <axel.polleres@deri.org> > Date: 23 November 2009 15:40:50 GMT+01:00 > To: "Marcelo Arenas" <marcelo.arenas1@gmail.com> > Subject: Re: RDB2RDF Working Group > > Hi Marcelo! > > Good to hear from you! > > First of all, can I share this conversation with the SPARQL WG/Chairs? > (I ask because you addressed to me alone) > > Now my answer: > > Looking forward to collaborate with you on the RDB2RDF side of the liaison with SPARQL... > Indeed the definition of integrity constraints such as keys and foreign keys is not a part of SPARQL. > In fact, SPARQL is not a data definition language: we define a query language (SPARQL/query [1]) and > a data manipulation language (SPARQL/update [2]), but aren't chartered for designing data definitions... > > Dataset descriptions, as far as we are concerned with (as a part of SPARQL/service descriptions [3]) > will be very basic, just providing hooks to data descriptions at most, that is a minimal set of properties to link to dataset descriptions in some external formalism (concretely void and saddle have been discussed earlier, > but we will most likely not actively promote a particular data definition language). > > I hope that clarifies matters. in fact, I'd honestly see the definition/description of constraints on datasets as something on the side of extensions of OWL/RDF Schema rather than on the side of SPARQL. That latter sentence is my personal view... probably something to be discussed/suggested in the upcoming "next steps on RDF" W3C workshop. > > best regards, > Axel > > 1. http://www.w3.org/TR/sparql11-query/ > 2. http://www.w3.org/TR/sparql11-update/ > 3. http://www.w3.org/TR/sparql11-service-description/ > > > > On 23 Nov 2009, at 15:29, Marcelo Arenas wrote: > >> Dear Axel, >> >> As you probably know, there is a new working group in the W3C whose >> mission is to standardize a language for mapping relational data into >> RDF and OWL (RDB2RDF WG). I am an invited expert in that group. >> >> The work on SPARQL is fundamental for the work of the RDB2RDF WG, so >> we would like to coordinate our efforts with that of the SPARQL WG. >> For that reason, I have volunteered to be the liaison between the >> RDB2RDF group and your group. >> >> Currently, we are trying to define the list of features of the data >> definition language of SQL that will be supported in the mapping >> language for relational data into RDF and OWL. One of these features >> is the definition of integrity constraints such as keys and foreign >> keys, so I was wondering whether you have discussed about the >> possibility of including integrity constraints in the data definition >> language of SPARQL. I took a look at the SPARQL WG Wiki and I couldn't >> find any reference about this, but maybe I am missing something. Thank >> you in advance for any information about this. >> >> Cheers, >> >> Marcelo >> >
Received on Monday, 23 November 2009 14:50:03 UTC