W3C home > Mailing lists > Public > www-rdf-interest@w3.org > May 2003

Re: Some RDQL questions

From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
Date: Thu, 15 May 2003 20:39:25 +0100
To: Alexander Jerusalem <ajeru@vknn.org>
Cc: "www-rdf-interest@w3.org" <www-rdf-interest@w3.org>
Message-ID: <20030515193925.GP22590@ecs.soton.ac.uk>

On Thu, May 15, 2003 at 08:02:39 +0100, Alexander Jerusalem wrote:
> My problem with this is that if the database backend doesn't handle 
> sorting, grouping and aggregating, I have to fetch the whole result set 
> from the database process and then do it without access to indexes. That's 
> a problem with large datasets.

Theres nothing from stopping you extending the RDQL sytax to include
ordering, or using an RDF store that has allready done so.

3store doesn't have ordering (yet) but it does have SQL style LIMIT and
OFFSET for chunking, adding order would be simple.

The lack of left joins is also something that has affected our client
developemnts, but we haven't looked at supporting that yet.
 
> Maybe I'm just abusing these technologies when I think of RDF as a flexible 
> database format, of OWL as a data modelling language and of RDQL as a data 
> query language. RDQL seems to suggest an in memory/in process view.

3store performs its RDQL queries entirly in the backend, whithout any in
memory processing. Its currenty not a complete implementation, but I don't
forsee any problems.

- Steve
Received on Thursday, 15 May 2003 15:39:30 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:59 GMT