- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Wed, 14 Dec 2011 09:45:18 -0500
- To: public-rdb2rdf-wg@w3.org
- Message-ID: <4EE8B67E.2050908@openlinksw.com>
On 12/14/11 8:44 AM, Juan Sequeda wrote: > > > On Wed, Dec 14, 2011 at 5:23 AM, Richard Cyganiak <richard@cyganiak.de > <mailto: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 the outdated and in many ways broken RDF/XML).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. +1 KIngsley > > > Best, > Richard > > > > > > > Thanks, > > - Souri. > > > > ----- Original Message ----- > > From: kidehen@openlinksw.com <mailto:kidehen@openlinksw.com> > > To: public-rdb2rdf-wg@w3.org <mailto: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 <mailto:richard@cyganiak.de> > >>>>> To: souripriya.das@oracle.com <mailto:souripriya.das@oracle.com> > >>>>> Cc: public-rdb2rdf-wg@w3.org <mailto: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 > <http://www.openlinksw.com/blog/%7Ekidehen> > > Twitter/Identi.ca handle: @kidehen > > Google+ Profile: https://plus.google.com/112399767740508618350/about > > LinkedIn Profile: http://www.linkedin.com/in/kidehen > > > > > > > > > > > > > > > > > -- 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
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Received on Wednesday, 14 December 2011 14:46:34 UTC