- From: Juan Sequeda <juanfederico@gmail.com>
- Date: Wed, 14 Dec 2011 08:44:12 -0500
- To: Richard Cyganiak <richard@cyganiak.de>
- Cc: Souripriya Das <souripriya.das@oracle.com>, kidehen@openlinksw.com, public-rdb2rdf-wg@w3.org
- Message-ID: <CAMVTWDxxPN04mFmhw6QOV_Q-SvMNAwYu1UjB7pGmxi_bn=7qyA@mail.gmail.com>
On Wed, Dec 14, 2011 at 5:23 AM, Richard Cyganiak <richard@cyganiak.de>wrote: > Souri, > > On 13 Dec 2011, at 23:40, Souripriya Das wrote: > > OWL too was called a language, "Web Ontology Language". But, it just > defined a vocabulary. It did not define any syntax. > > OWL defines three new syntaxes: > > http://www.w3.org/TR/owl2-syntax/ > http://www.w3.org/TR/owl2-xml-serialization/ > http://www.w3.org/TR/owl2-manchester-syntax/ > > > One can use any RDF syntax (RDF/XML, N-Triple, ...) for OWL. > > [[ > As noted above, any conformant OWL 2 tool MUST accept ontology documents > using the RDF/XML serialization … A conformant OWL 2 tool MAY also accept > ontology documents using other serializations, for example Turtle > ]] > http://www.w3.org/TR/owl2-conformance/#Tool_Conformance > > RDF/XML is the single normative OWL syntax. My desire is to have a single > normative R2RML syntax (but it should be Turtle rather than the outdated > and in many ways broken RDF/XML). > Ok. I'm now convinced. If RDF/XML is the single normative OWL syntax, then there should be a single normative R2RML syntax too... and RDF/XML is too complicated for this. So you got my vote for Turtle to be the "single normative R2RML syntax". However, other syntaxes *should* be supported by implementations. R2RML is basically a vocabulary. Written in Turtle, it looks like a language, but it's still a vocabulary. R2RML mappings are instantiations of this vocabulary. So technically, I can import the R2RML vocabulary into an ontology editor, and use the ontology editor to create the mappings. Does this really work right now? I don't know. Will people actually do this? I don't know. But it could. And all these tools support different syntaxes. So if I were to create an R2RML mapping using an existing ontology editor tool, export it as RDF/XML and send it to somebody else and they open it in an R2RML specific tool.. everything should work. > Best, > Richard > > > > > > > Thanks, > > - Souri. > > > > ----- Original Message ----- > > From: kidehen@openlinksw.com > > To: public-rdb2rdf-wg@w3.org > > Sent: Tuesday, December 13, 2011 5:01:24 PM GMT -05:00 US/Canada Eastern > > Subject: Re: What is Oracle's objection to the use of Turtle as R2RML > syntax? > > > > On 12/13/11 4:51 PM, Richard Cyganiak wrote: > >> Hi Ashok, > >> > >> On 13 Dec 2011, at 21:11, ashok malhotra wrote: > >>> At the Linked Data Workshop last week IBM showed some slides that used > a RDF syntax called Trig. > >>> So, I looked up Trig > http://www.wiwiss.fu-berlin.de/suhl/bizer/TriG/Spec/ and found that you > were > >>> one of the authors. So, Trig might be an alternate syntax for the > mapping language, no? > >>> Folks seemed to like it. It is not a standard but may become one. > >> I like that example! R2RML already allows the use of TriG syntax, no > change required. TriG is a superset of Turtle. If you serialize an R2RML > mapping graph as TriG, you get a Turtle file. > >> > >>> It is also possible that > >>> other RDF syntaxes will appear and one of them will become dominant. > If that happens, > >>> it would be good if users could write R2RML in the new syntax. > >> It takes a while for a new syntax to be invented, be implemented, be > evangelized, become popular, and become a W3C Recommendation. In the case > of Turtle, 13 years. A future RDB2RDF WG can relax the Turtle requirement > for a future R2RML version if demand for other syntaxes materializes. This > is not something that needs to be considered for R2RML 1.0. > >> > >> [[ > >> PROPOSAL: On ISSUE-57, let's just go with Turtle in order to get R2RML > 1.0 out of the door. > > > > +1 > > > > Kingsley > >> ]] > >> > >> Best, > >> Richard > >> > >> > >> > >>> All the best, Ashok > >>> > >>> On 12/13/2011 12:07 PM, Richard Cyganiak wrote: > >>>> Souri, what you say here is all correct (well, some nitpicks inline), > but I still don't see the key question addressed: What makes > one-w3c-RDF-syntax-MUST better in your eyes? All you do below is show that > users and implementers will have to go through extra hoops if that proposal > is accepted, so you're actually sort of making a case against it… > >>>> > >>>> On 13 Dec 2011, at 16:34, Souripriya Das wrote: > >>>>> There are currently two proposed options: > >>>>> 1) Turtle-syntax-MUST > >>>>> 2) one-w3c-RDF-syntax-MUST > >>>>> > >>>>> The Turtle-syntax-MUST option does not support any syntax other than > Turtle for the R2RML mapping documents > >>>> (Right, R2RML *mapping documents* MUST be Turtle. But implementations > MAY still support any syntax other than Turtle.) > >>>> > >>>>> while the one-w3c-RDF-syntax-MUST option only requires at least one > of the (W3C Recommendation) RDF syntaxes be used for R2RML mapping documents > >>>>> (while, because of the Turtle-convertibility, still allowing the > test cases, tutorials, books, etc. to be written in Turtle). > >>>> But one-w3c-RDF-syntax-MUST would equally allow tutorials and books > to be written in any other syntax, so we'll get books that teach R2RML > using RDF/XML syntax, tutorials that teach R2RML using RDFa syntax, et > cetera. > >>>> > >>>>> Again, here is the one-w3c-RDF-syntax-MUST proposal: > >>>>> [[ > >>>>> An R2RML mapping document is any document that encodes an R2RML > mapping graph and > >>>>> is written in any RDF syntax that is a W3C Recommendation and that > can be converted to Turtle. > >>>>> ]] > >>>>> (By "Turtle" we mean the future Turtle W3C Recommendation) > >>>>> > >>>>> The following can be said about the effect of using the above > proposal: > >>>>> > >>>>> ------------------ > >>>>> Consider an R2RML mapping document written in RDF/XML syntax: > >>>>> - Is it a conforming R2RML mapping document? > >>>>> YES. (for Turtle-syntax-MUST: NO) > >>>> …and this is literally the *only* difference. I don't understand who > benefits from this. Who is keen on calling an R2RML mapping graph > serialized in RDF/XML an R2RML mapping document, and why? > >>>> > >>>>> - Why? > >>>>> Because one can convert the document to generate an equivalent > document written in Turtle syntax. > >>>>> > >>>>> --------------------- > >>>>> Consider an R2RML mapping processor which ONLY accepts R2RML mapping > documents written in RDF/XML syntax: > >>>>> - Is it a conforming R2RML mapping processor? > >>>>> YES. (for Turtle-syntax-MUST: YES) > >>>>> - Why? > >>>>> Because it accepts all conforming R2RML mapping documents, written > in RDF/XML syntax. > >>>>> > >>>>> --------------------- > >>>>> Testing for conformance of an R2RML mapping processor that ONLY > accepts RDF/XML documents: > >>>> Yes, it's possible, but it's inconvenient for implementers. What > advantage balances this inconvenience? > >>>> > >>>>> For each test in "tests for conformance" > >>>>> 1) obtain the mapping documents (written in Turtle syntax) > >>>>> 2) Convert these Turtle-syntax mapping documents into RDF/XML syntax > (assuming this is possible) > >>>>> 3) Process the converted documents > >>>>> 4) Run the corresponding SPARQL queries from "tests for conformance" > and compare the results > >>>>> 5) If query results match, then this processor is indeed a > conforming R2RML mapping processor > >>>>> > >>>>> --------------------- > >>>>> Sharing of an R2RML mapping document between two non-overlapping > syntax accepting processors: > >>>> Yes, it's possible, but it's inconvenient for mapping authors and > admins. What advantage balances this inconvenience? > >>>> > >>>> I'm not saying that there is no advantage. I'm just saying that I > myself can't think of any, and that I can't recall anyone else mentioning > any! > >>>> > >>>> So, which stakeholder (WG members, implementers [incl. Oracle], > mapping authors) benefits from one-w3c-RDF-syntax-MUST, and how? > >>>> > >>>> Best, > >>>> Richard > >>>> > >>>> > >>>>> - MappingProcessor1 accepts ONLY RDF/XML and MappingProcessor2 > accepts ONLY N-Triples > >>>>> - an R2RML mapping document (written in RDF/XML) and used at > MappingProcessor1 is to be shared with MappingProcessor2 > >>>>> - convert the mapping document into an equivalent N-Triples document > (via Turtle, if direct conversion is not possible) > >>>>> - present the N-Triples R2RML mapping document to MappingProcessor2 > >>>>> > >>>>> Thanks, > >>>>> - Souri. > >>>>> > >>>>> ----- Original Message ----- > >>>>> From: richard@cyganiak.de > >>>>> To: souripriya.das@oracle.com > >>>>> Cc: public-rdb2rdf-wg@w3.org > >>>>> Sent: Wednesday, December 7, 2011 1:52:14 PM GMT -05:00 US/Canada > Eastern > >>>>> Subject: Re: What is Oracle's objection to the use of Turtle as > R2RML syntax? > >>>>> > >>>>> On 7 Dec 2011, at 18:07, Souripriya Das wrote: > >>>>>> Instead of the following definition of the mapping document: > >>>>>> > >>>>>> [[ > >>>>>> An R2RML mapping document is any document written in the Turtle > [TURTLE] RDF syntax that encodes an R2RML mapping graph. > >>>>>> ]] > >>>>>> > >>>>>> we propose the following: > >>>>>> > >>>>>> [[ > >>>>>> An R2RML mapping document is any document that encodes an R2RML > mapping graph and > >>>>>> is written in any RDF syntax that is a W3C Recommendation and can > be converted to Turtle [2]. > >>>>>> ]] > >>>>> Why is this better? > >>>>> > >>>>> Richard > >>>>> > >> > >> > > > > > > -- > > > > Regards, > > > > Kingsley Idehen > > Founder& CEO > > OpenLink Software > > Company Web: http://www.openlinksw.com > > Personal Weblog: http://www.openlinksw.com/blog/~kidehen > > Twitter/Identi.ca handle: @kidehen > > Google+ Profile: https://plus.google.com/112399767740508618350/about > > LinkedIn Profile: http://www.linkedin.com/in/kidehen > > > > > > > > > > > > > > > > >
Received on Wednesday, 14 December 2011 13:45:10 UTC