Re: RDF/OWL/Sparql and native XML databases

Henry,

SPARQL's CONSTRUCT (and likewise XSPARQL) doesn't support the creation 
of named graphs. Our design rationale was to neither extend SPARQL nor
XQUERY, but just to cleanly combine them. since creation of named graphs 
would support a respective extension of SPARQL, we do not have this 
feature.

If it is desired, then I guess this should go to the current discussion 
of desired features for a next iteration of sparql, see [1]
and the respective discussions on the sparql-dev mailinglist, see [2]
and the thread starting there.

I can imagine that such a thing would rather fall into the discussed 
update facilities, i.e. by using something like UPDATE INTO
from SPARUL [3], instead of CONSTRUCT. If a future version from SPARQL 
supports this or SPARUL is standardized, it would be only natural to 
have it also in  XSPARQL (or XSPARUL), actually, we are starting working 
on extending XSPARQL by SPARUL features already, but this is still in an 
early stage.

1. http://esw.w3.org/topic/SPARQL/Extensions
2.http://lists.w3.org/Archives/Public/public-sparql-dev/2008JanMar/0020.html
3. http://jena.hpl.hp.com/~afs/SPARQL-Update.html

Story Henry wrote:
> Just a question on this. Is it easy to put data into graphs with XSPARQL?
> 
> XML allows one to say anything and it does not clearly distinguish 
> contexts jumps. That means that a lot of xml out there is going to be 
> data about data. Take the very simple atom entry below:
> 
> <entry>
>      <title>syndeocms Project</title>
>      <link href="http://doapspace.org/doap/sf/syndeocms"/>
>      <id>http://doapspace.org/doap/sf/syndeocms</id>
>      <updated>2007-12-13T18:30:02Z</updated>
>      <summary>Some text..</summary>
>      <content type="text/rdf+n3">
>           @prefix doap: &lt;http://usefulinc.com/ns/doap#&gt; .
>           &lt;http://projects.com/1&gt; a doap:Project;
>                                         doap:name "Project 1" .
>      </content>
> </entry>
> 
> the xml in the content could be some other xml data format too, for 
> example HR-XML.
> A interesting translation of the above, where the content itself gets 
> semantically transformed, would be in N3
> 
> @prefix doap: <http://usefulinc.com/ns/doap#> .
> @prefix : <http://bblfish.net/work/atom-owl/2006-06-06/#> .
> 
> [] a :Entry
>   :title "syndeocms Project";
>   :alternate <http://doapspace.org/doap/sf/syndeocms>;
>   :id "http://doapspace.org/doap/sf/syndeocms"^^xsd:anyURI;
>   :updated "2007-12-13T18:30:02Z"^^xsd:dateTime;
>   :summary "Some text";
>   :contentGraph {
>       <http://projects.com/1> a doap:Project;
>                               doap:name "Project 1" .
>   }
> 
> Note: It is interesting how this kind of context switch can make XPath 
> expressions somewhat tricky to write, since if one is not careful one 
> could xpath oneself through a context boundary to a piece of content 
> that is not being affirmed.
> 
> Notice also how the entry has a content, that is a graph, but not a 
> named one.
> So of course one could just, as atom owl does, keep the content as a 
> literal, but it would make queries across contexts opaque. I am thinking 
> of transforms such as: I believe what Jim affirms Jane said on his trip 
> to New York.
> 
> Henry
> 
> 
> 
> On 10 Jul 2008, at 12:14, Story Henry wrote:
> 
>> Very neat. I like the way this reduces the need to have to go through 
>> an intermediate format to get the data into an rdf store.  Inversely 
>> it is very nice how it gets the rdf data into a simple xml format.
>>
>> Henry
>>
>> On 10 Jul 2008, at 09:13, Olivier Rossel wrote:
>>
>>>
>>> You may want to have a look at XSPARQL, that was presented at ESWC 2008:
>>> http://www.eswc2008.org/final-pdfs-for-web-site/qpI-1.pdf
>>> http://xsparql.deri.ie/
>>
> 


-- 
Dr. Axel Polleres, Digital Enterprise Research Institute (DERI)
email: axel.polleres@deri.org  url: http://www.polleres.net/

Everything is possible:
rdfs:subClassOf rdfs:subPropertyOf rdfs:Resource.
rdfs:subClassOf rdfs:subPropertyOf rdfs:subPropertyOf.
rdf:type rdfs:subPropertyOf rdfs:subClassOf.
rdfs:subClassOf rdf:type owl:SymmetricProperty.

Received on Thursday, 10 July 2008 11:49:45 UTC