- From: Dan Brickley <danbri@w3.org>
- Date: Tue, 28 Sep 2004 07:29:22 -0400
- To: public-rdf-dawg-comments@w3.org
- Cc: danbri@w3.org, kal@techquila.com, phil@icra.org
DataAccess WG., some more notes re http://www.w3.org/TR/rdf-dawg-uc/ and design choices. While acknowledging http://www.w3.org/Provider/Style/URI I'd like to report on an RDF query use case from the labelling and filtering application area. Specifically there are a number of systems which allow content labels to be 'attached' to every resource (typically a document) that has a URI which begins-with, ends-with, contains or matches some candidate string. W3C's own PICS format (precursor to PICS-NG aka RDF itself) has such a mechanism. I wouldn't expect DAWG to try to replicate this entire feature of PICS, but I do suggest that the WG consider making it possible for string match operations on URIs to be allowable. While keying metadata off of URI structure is not to everyone's tastes, in practice there are many sites that do organise their information in ways that are reliably reflected into URI structure. It seems natural that an RDF database, exposed via DAWG's QL + protocol, should be usable within a system that exploits such regularities to associate general labels with classes of document that share certain naming patterns. (I'd also hope to be able to use OWL to reason about those common labels, but that's a separate story). Possible use case story: [[ XYZ has collected a very large database of Web content labels expressed in RDF. The labels use a custom vocabulary which asociated generally applicable content descriptions with information about the rules for applying these general labels to specific documents. These application rules are typically expressed using string-matches against document URIs. The ability to manage this metadata in terms of generalisations against classes of document is important to XYZ, since it lowers costs and increases the likelihood that a description can be found that applies to any given URI. Some of these labels are provided by the content creator, others are 3rd party annotations. The intent is to store them all in an off-the-shelf RDF system and build applications that exploit this information. XYZ is attending an evening class on Description Logic and hopes to eventually make use of the generalised description facilities in W3C's OWL standard. In the meantime, millions of RDF triples have to be stored and retrieved in an efficient manner, so XYZ looks to DAWG-compatible RDF data storage systems. XYZ would be delighted to be able to have a product-neutral, standard way of asking such a database questions like "what documents have URIs that begin http://example.com/pics/adult/ ?", "what documents have URIs that end ".png"?, "what documents have URIs that contain the string "/adult/"?, so that such matching could be done within the database rather than in application code. ]] Hope this helps. IMHO being able to do this would be hugely useful, cheers, Dan ps. copying Kal and Phil, whose work this relates to. All mistakes are mine etc etc.
Received on Tuesday, 28 September 2004 11:29:22 UTC