Re: RDF2RDB 0.5

could be very useful!

(anything that avoids the use of sparql must be useful)
</joke>

 however, suspect that there is a modelling challenge
and possibly some software already exists that does that

modelling challenge:

to create relational databases,  it is necessary to model data
ie to define  what to put in columns , in raws, the granularity, and a
bunch of other stuff, including normalisation (check codds relational
principles)

this is conceptual work that only an intelligent and trained human can
do (that I know of) and even so, its hardly 'right' or 'wrong' rather
a function of purpose (variable, not standardizable)

RDF, from what I know, is typically unstructured data
(unless it has been RDFIZED form data previously modelled and
extracted from DBs, but I assume this is not the kind of RDF that you
are targeting here)

 what you propose, as I understand it, could be useful if you can get
the system to model/represent rdf unstructred into
meaningful/structured relational data

If however you could come up with a web service that enables a user to
create structured data models from unstructured ones, then I think
that would be groundbreaking work and I d love to see something
(unless its already available and I am not aware of it then please point)

cheers

PDM





On Sun, Aug 5, 2012 at 2:03 AM, Michael Brunnbauer <brunni@netestate.de> wrote:
>
> hi all
>
> to support the proliferation of RDF, I have begun work on a tool to convert
> RDF data into relational databases. It is intended for people who want to use
> data available only as RDF but do not have the patience to install a triple
> store and learn SPARQL. I know there are tools that present a SQL view
> over a triple store but installing such an environment also is quite
> challenging.
>
> There has been work on real "converters" in the past, especially the paper from
> Wajee Teswanich and Suphamit Chittayasothorn:
>
>  http://hcotuk.etu.edu.tr/semanticweb/A%20Transformation%20from%20RDF%20Documents%20and%20Schemas%20to%20Relational%20Databases.pdf
>
> My tool works much like the one described in this paper (has it ever been
> implemented ?), with important differences:
>
> -It supports incremental runs (adding more RDF data to a database later)
>
> -It supports entailment (rdfs:subClassOf, rdfs:subPropertyOf, rdfs:domain,
>  rdfs:range, owl:equivalentClass, owl:equivalentProperty,
>  owl:FunctionalProperty)
>
> The software is written in Python and uses the RDFLib Python library. It works
> with local and remote files. You can find more information and download it at
>
>  http://www.netestate.de/De/Loesungen/RDF2RDB
>
> There also example database dumps for
>
>  http://www.w3.org/People/Berners-Lee/card.rdf
>
> and
>
>  http://www.w3.org/People/Berners-Lee/card.rdf
>  +
>  http://xmlns.com/foaf/spec/index.rdf
>
> there.
>
> Don't rant about the invalid skolem URIs - you can set the skolem URI prefix
> to something valid in the configuration :-)
>
> So far this has just been fun and I would like to have some feedback on the
> usefulness before I spend more time on it.
>
> Regards,
>
> Michael Brunnbauer
>
> --
> ++  Michael Brunnbauer
> ++  netEstate GmbH
> ++  Geisenhausener Straße 11a
> ++  81379 München
> ++  Tel +49 89 32 19 77 80
> ++  Fax +49 89 32 19 77 89
> ++  E-Mail brunni@netestate.de
> ++  http://www.netestate.de/
> ++
> ++  Sitz: München, HRB Nr.142452 (Handelsregister B München)
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> ++  Prokurist: Dipl. Kfm. (Univ.) Markus Hendel
>

Received on Sunday, 5 August 2012 14:53:27 UTC