- From: Young,Jeff (OR) <jyoung@oclc.org>
- Date: Thu, 9 Jun 2016 20:29:36 +0000
- To: Martynas Jusevičius <martynas@graphity.org>, "David Booth" <david@dbooth.org>
- CC: Semantic Web <semantic-web@w3.org>, Andy Seaborne <andy@seaborne.org>, "Fabien.Gandon@inria.fr" <Fabien.Gandon@inria.fr>
I find myself processing RDF graphs in Hadoop sometimes. I usually strip all the CR/LF characters from the RDF/XML and then write the output like so: <graphURI>\t<rdf:RDF>…</rdf:RDF> <graphURI>\t<rdf:RDF>…</rdf:RDF> Etc. That makes it easy to process as RDDs. http://spark.apache.org/docs/latest/programming-guide.html#resilient-distributed-datasets-rdds Depending on what the goal is, that might be a useful approach. The RDF/XML vs other RDF serializations isn’t that critical, as long as the CR/LF doesn’t become a factor. Otherwise it’s harder to know when one graph ends and the other begins. Jeff On 6/9/16, 4:00 PM, "Martynas Jusevičius" <martynas@graphity.org> wrote: >Yes, I am using an RDF/XML dialect, but it's a perfectly standard >dialect. I wish it would be standardized as some kind of profile. > >I have heard all these arguments before. But I know what I'm doing -- >as mentioned, we have been using XSLT quite successfully. > >Turtle and JSON-LD are fine, but they're simply not XML, and I don't >think transforming them with Javascript or another imperative language >is any more natural than transforming RDF/XML with XSLT. > >Anyway, I was asking about named graphs :) > >P.S. Sorry if you get multiple copies, I need to sort out my email aliases... > >On Thu, Jun 9, 2016 at 9:29 PM, David Booth <david@dbooth.org> wrote: >> On 06/09/2016 02:20 PM, Martynas Jusevičius wrote: >>> >>> Honestly I don't understand why RDF/XML is getting such a bad rap :) >> >> >> Key reasons: >> >> 1. Other (more modern) RDF serializations are far more >> human friendly, such as Turtle or even JSON-LD. >> >> 2. RDF/XML does not play well with standard XML tooling, >> such as XSLT, XML Schema or RelaxNG. >> >> 3. RDF/XML misleads people into thinking that RDF is a >> dialect of XML, and it is not. >> >> As Kingsley stated on 3 September 2015: >>> The problem with RDF/XML is that it had an exalted position >>> in the Semantic Web realm for way too long. To this very day, >>> many of us are still trying to get folks to understand that >>> RDF is neither a format nor a dialect of XML. >> >> I too have spent too many painful hours coaching XML ninjas >> who were misled in exactly that way, and were performing all >> sorts of unnatural acts in XSLT in ultimately doomed efforts >> to process RDF/XML as though it were "regular" XML. >> >> I don't mean to disparage RDF/XML. RDF/XML was the best that >> we had when it was created. But we have much better serializations >> for RDF now, such as Turtle/TriG and JSON-LD. >> >>> Sure, the spec could have been better with fewer variations, but if >>> you don't do nesting and keep descriptions "flat", the output is >>> perfectly predictable. That is the default Jena output and we have >>> been transforming it for years. >> >> >> Then you are using a particular, restricted dialect of RDF/XML that happens >> to be produced by Jena -- not RDF/XML in general. >> >> David Booth >> >>> >>> It is a convenient XML structure when related stuff is grouped under a >>> parent element, such as properties of a resource, or resources of a >>> graph. RDF/XML can provide that, TriX and SPARQL XML results cannot. >>> >>> On Thu, Jun 9, 2016 at 8:06 PM, David Booth <david@dbooth.org> wrote: >>>> >>>> On 06/09/2016 11:44 AM, Martynas Jusevičius wrote: >>>>> >>>>> >>>>> Hey, >>>>> >>>>> we have a use case where we need an RDF format in XML syntax that >>>>> 1. supports named graphs >>>>> 2. has a convenient structure for XSLT transformations >>>>> >>>>> RDF/XML fails at #1, TriX fails at #2. >>>>> >>>>> I suggest extending RDF/XML with a concept of named graph, >>>> >>>> >>>> >>>> Please don't. The more we can get away from RDF/XML the better. >>>> >>>> How about using the W3C standard SPARQL 1.1 XML results format, with >>>> quads: >>>> subject, predicate, object and graph? >>>> https://www.w3.org/TR/rdf-sparql-XMLres/ >>>> >>>> David Booth >>> >>> >>> >>> >> >
Received on Thursday, 9 June 2016 20:30:09 UTC