- From: Peter Frederick Patel-Schneider <pfps@research.bell-labs.com>
- Date: Thu, 13 Oct 2011 07:44:44 -0400
- To: <ian.davis@talis.com>
- CC: <public-rdf-wg@w3.org>
From: Ian Davis <ian.davis@talis.com> Subject: Strawpoll proposals on terminology Date: Wed, 12 Oct 2011 16:22:20 -0500 > I think we would get understand the extent of consensus in the group if we ran > some strawpolls on usage of our terminology with some concrete statements > > I restated some definitions from SPARQL 1.1 using explicit RDF Graph and RDF > Container terminology. I also extended the idea of explaining in prose what > certain SPARQL queries mean. I finally threw in a few statements that push the > boundaries of what we discussed today. > > S0) The state of a Graph Container is an RDF Graph. > > S1) A Graph Store contains one (unnamed) slot holding a default Graph Container > and zero or more named slots holding named Graph Containers. > > S1a) A Graph Store contains one (unnamed) default Graph Container and zero or > more Graph Containers each associated with a IRI. > > S2) An RDF Dataset is a set { G, (<u1>, G1), (<u2>, G2),... (<un>, Gn) } where G > and each Gi are RDF Graphs and each <ui> is an IRI. > > S3) The RDF Graphs in an RDF Dataset are the states of the Graph Containers > contained in the Graph Store. > > The following all assume <g> is associated with a Graph Container in the Graph > Store > > S4) When we write SELECT * WHERE { GRAPH <g> {?s ?p ?o} } we mean the SPARQL > engine should retrieve the RDF Graph that is the state of the Graph Container > that <g> is associated with and evaluate the graph pattern against the RDF > Graph. > > S5) When we write INSERT DATA { GRAPH <g> { :s :p :o } } we mean the SPARQL > engine should retrieve the RDF Graph that is the state of the Graph Container > that <g> is associated with, perform an RDF-Merge operation between that RDF > Graph and :s :p :o and set the state of <g> to be the resulting graph. > > S6) When we write DELETE DATA { GRAPH <g> { :s :p :o } } we mean the SPARQL > engine set the state of the Graph Container that <g> is associated with to the > empty RDF Graph So far so good. S7 is an attempt to push the metatheory of graph containers into an RDF theory. I am not convinced that this is a good idea. > S7) When we write SELECT * WHERE { GRAPH <g> {?s ?p ?o} } the triple <g> > rdf:type :GraphContainer is true for some <g> > > S7a) When we write SELECT * WHERE { GRAPH <g> {?s ?p ?o} } the triple <g> > rdf:type :GraphContainer is true for all <g> S8 pushes a much-too-strong notion of the abiogenesis of RDF graphs. > S8) When ASK WHERE { GRAPH <g> { :s :p :o } } evaluates to true and <g> is an > http IRI then at some time in the past an HTTP GET request to <g> has returned a > document that when parsed results in a graph that contains the triple :s :p :o > > -- > Ian Davis, Chief Technology Officer, Talis Group Ltd. > http://www.talis.com/ | Registered in England and Wales as 5382297 > peter
Received on Thursday, 13 October 2011 11:45:53 UTC