Re: Announcing RDFdb

(what Guha _meant_ to say was that this is a semistructured 
database for XML-powered Web apps that use an edge-labelled 
graph datamodel.  Like RDF :-)

<ducks/> 

However described, it's a nice bit of work and (judging by the
linux binary) a good step towards shrinkwrappability of RDF
database/query/parser tools. So please send Guha lots of bug reports (and
fixes...).

The query language aspect is interesting, and perhaps worth discussing
here. The current system uses SQL-ish textual query strings rather than
the use-markup-for-all-structure philosophy. Other systems I've seen have
a similar but not the same approach. It'd be good to have some
basis for interchanging queries (and inference rules) between applications
like RDFdb. Which raises a bunch of issues, one of which i'm currently
puzzling over: how do we represent query variables to RDF? 

This cropped up in the DanC/Jos discussion of inference rules recently[1],
where Dan quite reasonably objected to "recognizing variables by their
spelling". I really don't know which approach makes sense for this right
now, but still I find 'var:' appealing, much as 'phone:', or 'java:' etc
can be used for homegenous regions of the URI namespace. That said,
claiming a toplevel URI scheme is serious business; maybe just using
http://example.com/variables/foo would be just as good. DanC's model is
intriguing, but doesn't really address the issue of which URIs do we use
to identify the variables in some representation of a query. (I think his
answer is 'any will do'...)

Has anyone else come up with models for representing variables over
RDF? Might be fun to write translations to/from Guha's RDFdb language, for
example...

 --dan

[1] http://lists.w3.org/Archives/Public/www-rdf-interest/2000Jul/0028.html

On Tue, 25 Jul 2000, Guha wrote:

> Hi,
> 
>  I'd like to announce the first release of RDFdb
> (http://www.guha.com/rdfdb/).
> 
>  RDFdb is an open source (under the MPL) scalable triple database server
> with a
> SQL-like front end. Its written in C with a perl client.
> 
>  You can download a linux binary or the source from the above url.
> 
>   I'd appreciate any comments, feedback, bug reports, bug fixes, ...
> 
>  thanks,
> 
>  Guha
>

Received on Tuesday, 25 July 2000 16:16:22 UTC