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Re: OODBMS <-> RDF

From: José Pedro Ferreira <jose.pedro.ferreira@cern.ch>
Date: Wed, 30 Jan 2008 10:46:37 +0100
Message-ID: <47A0477D.1030106@cern.ch>
To: <semantic-web@w3c.org>
Dear all,
Thank you so much for all the suggestions that you promptly provided!
I'm currently taking a look at the extensive amount of information 
provided by Elisa and Niklas, and I see that there's already a lot of 
work in this area, though things are still a bit immature.
Niklas, I'd really appreciate if you could provide me some information 
about this python structures <-> rdf transforms provided by oort, since 
I already have a layer that makes this kind of transformation in order 
to export JSON. So, maybe it will be useful.

Thanks, once again,
Cheers,

Pedro


Niklas Lindstrm escreveu:
> Hi!
>
> This is *very* interesting. I am behind Oort [1] (which Jesse
> mentioned). One of the ideas driving it is to have a mapping *both*
> back and forth between object and RDF graphs. Since it's Python, there
> may be some ground for what you're after. Specifically, Oort today
> allows you to construct RDF from Python dict/list/atomic value
> structures [2] (isomorphic to JSON, which you can load directly via
> simplejson). If you can get these structures from the ZODB, I hope
> Oort will take you to the RDF you need.
>
> A missing piece of the puzzle is generating mappers directly out of
> OWL schemas (and possibly vice versa). But these mappers also
> represent queries/aspects, which are more ragged and mixed, so this
> merits more investigation.
>
> ... Going further and beyond...
>
> In a wider sense, the Oort ("Out Of RDF Transmogrifying") idea right
> now is a tiny beginning of what I feel can be a promising way of
> bridging the gap between RDF and current pragmatic ("less is more")
> approaches that have emerged, such as microformats and JSON (along
> with the nascent ideas of schemas for those, as proposed by James
> Clark [3, 4] and e.g. the Mozilla team [5]). Much of what is discussed
> regarding Atom extensions [6] also seem (to me) to point towards a
> need for formalism "reduction" to fit more narrow contexts (by which I
> mostly mean to reuse OWL ontologies in simpler scenarios, where I'm
> afraid proper RDF continues to be "beyond the horizon").
>
> I do think RDF is a "grand unifier" for modelling, but it seems that
> for many specific contexts, it is viewed as "too formal" to get
> traction. It's not impossible, but hard, to sell RDF as a perfect
> match for smaller/local data syndication efforts. This poses the risk
> of continued reinvention of many things RDF solves very well
> (precision, I18N, data- and resource typing etc.). I believe that any
> given context provides assumptions and locality (of terms etc) that
> makes the decontextualized data which RDF is about *seem* superfluous.
> But that next step is then always left unresolved, causing all these
> integration problems that I assume many of us Semantic Web followers
> see a solution for in RDF, OWL, SPARQL etc.
>
> Basically, I consider simpler representations to be wrapped in context
> to reduce formal details, and I am convinced that that can be mapped
> to the RDF data model rather unobtrusively. How is what I've only
> begun scratching on the surface of..
>
> I've wanted to get the time and energy to pitch this more formally,
> but haven't gotten around to it much (more than with this message, and
> a related blog post [7] last year).
>
> Where to go further then? I'd gladly invite you to join
> <http://groups.google.com/group/oort>, which due to nigh zero activity
> I'd happily recast from a python toolkit focus into the more general
> vision I described above. Not the least since my scope has widened to
> plans for e.g. a javascript version of the Oort mapper, as well as
> examination of the Elmo [8] effort from the OpenRDF/Sesame people,
> which looks very similar to this. Granted, I do not have the
> experience yet to organize larger community efforts, so perhaps some
> other form would work better? I'm happy to join any party interested
> in this.
>
> (By analogy, this can be related to things as diverse as the relative
> merits of dynamic, static and inferred typing in programming, ORMs for
> RDBMSs, CouchDB-like technology, etc. Akin to "how to have the cake
> and eat it too".. I believe we can do this. With insulated layers,
> each simple and formal, as in many other cases.)
>
> Best regards,
> Niklas
>
> [1] <http://oort.to/>
> [2] <http://oort.to/oort_api/oort.test.test_rdfview-pysrc.html#test_from_dict>
> [3] <http://blog.jclark.com/2007/04/do-we-need-new-kind-of-schema-language.html>
> [4] <http://blog.jclark.com/2007/04/xml-and-json.html>
> [5] <http://developer.mozilla.org/en/docs/Describing_microformats_in_JavaScript>
> [6] <http://www.imc.org/atom-syntax/mail-archive/threads.html#20299>
> [7] <http://dustfeed.blogspot.com/2007/01/knowledge-bits-and-pieces.html>
> [8] <http://openrdf.org/doc/elmo/1.0-beta2/user-guide/>
>
>
>
>
> On Jan 26, 2008 12:12 AM, Jesse Erdmann <jesse@jesseerdmann.com> wrote:
>   
>> The only other D2R like software I'm aware of is Squirrel RDF,
>> http://jena.sourceforge.net/SquirrelRDF/.  I don't know of any support
>> of ZODB.  Is something like RDF Alchemy,
>> http://www.openvest.com/trac/wiki/RDFAlchemy, or Oort,
>> http://oort.to/, similar to what you're looking for?
>>
>> 2008/1/25 Jos Pedro Ferreira <jose.pedro.ferreira@cern.ch>:
>>
>>     
>>> Hello.
>>> Yes, I know that RDF can be seen as object-oriented. But... I'm not
>>> considering if it is possible to display OO data using RDF, but rather
>>> how to make this translation in a smooth, fairly automatic way, without
>>> having to write enormous amounts of replicated code, and taking
>>> advantages of the similarities that exist between the two models. It's a
>>> matter of "translation techniques".
>>>
>>> Cheers,
>>>
>>> Pedro
>>>
>>> cdr escreveu:
>>>
>>>       
>>>> On Fri Jan 25, 2008 at 02:34:28PM +0100, Jos? Pedro Ferreira wrote:
>>>>
>>>>         
>>>>> Hello.
>>>>> I need to make data stored in an object-oriented (ZODB) database available
>>>>> as RDF. I've been looking for existing architectures and mapping
>>>>> techniques, and eventually found D2RQ
>>>>> <http://www4.wiwiss.fu-berlin.de/bizer/D2RQ/spec/>. The problem is that
>>>>> D2RQ seems too much oriented towards the relational paradigm.
>>>>> Is there any research done on this particular area? I've been thinking
>>>>> about something similar to D2RQ, but object-oriented. However, I'd like to
>>>>> know if there's any work already done about this subject.
>>>>>
>>>>>           
>>>> your OOobject is your RDFsubject, your OOobject property is your RDFpredicate, and your OOobject property's value(s) is/are your RDFobject(s) (mind the nameclash)
>>>>
>>>> your OOobject have URI fields, of course.
>>>>
>>>> this also works with JSON.. which can be thought of as an OOobject serialization, and compatible with RDF so long as your property-symbols are URIs and each JSONobject has a URI property
>>>>
>>>>
>>>> theyre pretty much identical. even RDFs with its subclassing and subtyping is an OO model.. replace 'object' with 'resource' in the literature
>>>>
>>>>
>>>>
>>>>         
>>>>> Thanks in advance,
>>>>>
>>>>> Pedro
>>>>>
>>>>>           
>>>>         
>>>>> begin:vcard
>>>>> fn:Jose Pedro Ferreira
>>>>> n:Ferreira;Jose Pedro
>>>>> org:CERN;IT-UDS-AVC
>>>>> adr:;;;Geneva;;;Switzerland
>>>>> email;internet:jose.pedro.ferreira@cern.ch
>>>>> title:Software Developer
>>>>> tel;work:+41 22 76 75025
>>>>> tel;cell:+41 763 045 795
>>>>> x-mozilla-html:FALSE
>>>>> url:http://www.zarquon.biz
>>>>> version:2.1
>>>>> end:vcard
>>>>>
>>>>>
>>>>>           
>>>>
>>>>         
>>>       
>>
>> --
>> Jesse Erdmann
>> jesse@jesseerdmann.com
>> Twitter: http://twitter.com/jesseerdmann
>> Blog: http://blog.jesseerdmann.com/
>>
>>
>>
>>     


Received on Wednesday, 30 January 2008 09:46:55 GMT

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