- From: Michael Schneider <m_schnei@gmx.de>
- Date: Wed, 31 Jan 2007 22:14:20 +0100
- To: adamsobieski@hotmail.com
- CC: semantic-web@w3.org
Hi Adam! Adam wrote: > It occurs that in all the things that can be resources, one that is > missing is a statement residing in another document. > > I propose for consideration a syntax convention resembling: > > "http://yourdomain.com/yourdocument.rdf!123" to indicate that the > resource I wish to discuss or describe is the 123rd triple in the > triples representation of the document at that address. What you suggest here is to reference an RDF triple by its position within its containing RDF-graph's /serialization/. An (abstract) RDF graph is meant to be a /set/, and so its triples do not have any specific order. The order within the document does not have any RDF-related relevance: Every document consisting of a permutation of the triples will be deserialized into exactly the same RDF graph. So, your proposed URI format will loose its usage in the moment when the document is deserialized into an RDF graph. That is different from an URI in '#'-notation: A #-URI is (by convention) used to reference some resource (or its description) within an RDF graph, independent from any concrete serialization syntax: After deserializing some, say, RDF/XML document, it is still perfectly clear, what resource is referenced by such a #-URI. But even if you are really interested in referencing the triples within a concrete RDF document, you often cannot count on the order of its content. Say, you have the following document URL: http://www.example.org/foo.rdf But, perhaps, this document does not really exist as a static file at server side. Instead, the (semantic) web server might generate it dynamically in the moment when it is accessed, by assembling its content from information within some database. You cannot expect the database owner to store additional ordering information within its database, because such an ordering is, as I pointed out above, of no relevance from an RDF point of view. And you also cannot expect the applied assembly algorithm to behave deterministically, so it is not warranted that it will always produce exactly the same document. Best regards, Michael
Received on Wednesday, 31 January 2007 21:21:11 UTC