Thursday, September 26, 2013

RDF Named Graphs

Background


  1. “RDF Graph Identification” Unofficial Draft 15 August 2012
  2. Graph Terminology (w3c wikipage; covers g-box, gsnap, etc)
  3. Graphs Design 6.1 wiki page with some test cases (Apr 2012)
  4. Graphs Design 6.1/Sem some stuff about formal semantics for the use cases in 2 (April 2012)
  5. TriX
  6. TriG
  7. Named Graphs (pdf) 2005 preprint, Carroll et al.
  8. Named Graphs, Provenance, and Trust (pdf) Undated, Carroll et al.
Recent threads on W3 mailing lists:
  1. rdfs:Graph ? comment on http://www.w3.org/TR/rdf11-concepts/#section-dataset and issue 35 - original thread on public-rdf-comments list commenting on named graphs
  2. Re: rdfs:Graph ? comment on http://www.w3.org/TR/rdf11-concepts/#section-dataset and issue 35 - continuation of 1, moved to www-archive list
  3. defn of Named Graph - continuation of 2 on www-archive
Some older threads:

  1. http://lists.w3.org/Archives/Public/public-rdf-wg/2012Apr/thread.html - lots of stuff on named graphs, layers, etc

Facts on the ground: what people think and say about named graphs

  • Wikipedia on Named Graph
  • MANAGING RDF USING NAMED GRAPHS - longish blog article(Leigh Dodds, 2009).  "Named Graphs turn the RDF triple model into a quad model by extending a triple to include an additional item of information. This extra piece of information takes the form of a URI which provides some additional context to the triple with which it is associated, providing an extra degree of freedom when it comes to managing RDF data."
  • Named graphs for Jena

Terminology and Concepts

Example:

  1. :g { :a :b :c. }
  2. GRAPH :g { :a :b :c. }

I'll call :g a graph IRI and :b a property IRI.  Similarly, given {:a :a rdfs:Class}, I'll call :a a class IRI.  etc.