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issue#rdfSemantics : use cases

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Wed, 14 Sep 2005 10:54:51 +0100
Message-ID: <4327F36B.2060605@hp.com>
To: RDF Data Access Working Group <public-rdf-dawg@w3.org>


==== Use Case 1 : Publishing on the Web

When putting a service up on the web for other people/applications to access, 
it is highly desirable to follow RDF semantics - in particular, the results of 
querying equivalent graph should be equivalent.

"equivalent" does not necessarily mean identical, but we would need an account 
of how they were equivalent.

== Data 1:
:x <p> "z"  .
_:a <p> "z" .
== Query:
SELECT * { ?s ?p ?o }

== Results
s/:x  p/<p>  o/"z"

or

s/:x  p/<p>  o/"z"
s/_:a p/<p>  o/"z"


because the bNodes subject triple is not necessary and the graph is equivalent to

== Data 2:
:x <p> "z"  .

so we should have equivalent answers either by defining SPARQL so they are the 
same or saying how they are equivalent.  Making the same would be good.


==== Use Case 2 : Building a Graph

Use case:
"2.17 Building Ontology Tools (Semantic Web)"
http://www.w3.org/TR/rdf-dawg-uc/#u2.17

which I am reading to cover modification of the ontology in the editor as 
well.  While we are not addressing update in SPARQL, SPARQL could be used as 
part of an editing and update application.

Requirement:
"3.5 Local Queries"
http://www.w3.org/TR/rdf-dawg-uc/#r3.5

and comments in the thread:
http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Jun/0039.html

Together, these amount to access the abstract syntax of the RDF graph.  For 
example, the application will next modify the graph so that previous leaning 
is no longer valid.

== Data 1:
:x <p> "z"  .
_:a <p> "z" .

== Query:
SELECT * { ?s <p> ?o }

== Results
s/:x  p/<p>  o/"z"
s/_:a p/<p>  o/"z"

And the application wishes to add:
_:a <q> "y" .

that is, a tripe with the bNode in the abstract syntax form of the grap as 
subject.

This requires both solutions to be returned in the example query.

	Andy
Received on Wednesday, 14 September 2005 09:55:24 GMT

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