Re: Querying dbpedia from the command line?

On 18 Sep 2008, at 02:48, Bob DuCharme wrote:
> As a side note, I think this is going to be very big, because while  
> Linked Data (and much of the semantic web) is theoretically about  
> exposing data to programs instead of to eyeballs like the  
> traditional web, most of the linked data and semantic web demos I  
> see out there are about visual browsing of linked data--displaying  
> it to eyeballs. When we can grab the results of a linked data SPARQL  
> query with a script, then we can really start doing new and  
> interesting things with it.

I agree. Let me add some random thoughts on how to take this idea  
(retrieving data from RDF sources on the command line for further  
processing) into more powerful directions.

1. SPARQL is great, but too verbose for the command line. I would  
really like to use a single-line, XPath-style query language for RDF  
in situations like this. There are a couple of proposals for such a  
language out there, several of them are called "RDFPath" and there's  
Uche Ogbuji's Versa. It would be really great to see some progress in  
this area. The first one of these languages to get a well-packaged  
implementation on top of the Jena API will probably win.

2. I really like the idea behind the Semantic Web Client Library (part  
of NG4J) for exactly the reason you state above -- it makes it  
possible to get data from the sources out there for further  
processing. It has a command line tool that allows you to ask SPARQL  
queries against (potentially) the entire Web. Unfortunately, we never  
managed to get the library beyond a prototype stage, and a lot of work  
remains to be done on it. Still, the idea remains valid and is  
important, I think.

3. We are all waiting for SPARQL processors that federate multiple  
SPARQL endpoints transparently into a single endpoint. Progress is  
being made in this area, but it's slow. Meanwhile, there is a very  
nice 80/20 solution to this problem: Andy Seaborne has implemented a  
SERVICE keyword for his extended variant of SPARQL, which allows you  
to address parts of a SPARQL query to a specific endpoint. This seems  
like an easy win for data integration demos.


> Bob

Received on Thursday, 18 September 2008 11:30:01 UTC