- From: Patrick Stickler <patrick.stickler@nokia.com>
- Date: Thu, 18 Mar 2004 08:15:10 +0200
- To: public-rdf-dawg@w3.org
A client wishes to discover all resources which are of rdf:type ex:Person, and have an ex:ageInYears which is between "16"^^ex:count and "18"^^ex:count, inclusive. The client is aware of a knowledge source from which such resources might be discovered. Following the DAWG recommendation, the client formulates a query which expresses the desired characteristics to match and submits the query to the knowledge source. The knowledge source returns zero or more resource descriptions describing the matched resources. -- I deliberately used unknown datatypes in this example to illustrate the need to be able to allow arbitrary datatypes in input queries, regardless of what datatypes a particular query resolution engine may be able to handle. Note that if the client is able to include auxiliary knowledge which may be relevant to resolution of the query along with the query itself (e.g. in a single input RDF graph) this would allow the client to provide information about the terminology used in the query, such as about the nature of particular datatypes, their relationship to other datatypes, and even references to formal definitions of the datatypes which could be used by the knowledge source to evaluate typed literals and perform comparisons. E.g. the auxiliary knowledge could indicate an XML Schema which defines the datatype in question, and if the knowledge source is able to understand XML Schemas, could load and utilize to deal with values of that datatype. -- Patrick Stickler Nokia, Finland patrick.stickler@nokia.com
Received on Thursday, 18 March 2004 02:18:25 UTC