- From: Jeni Tennison <jeni@jenitennison.com>
- Date: Mon, 18 Jan 2010 19:56:47 +0000
- To: Leigh Dodds <leigh.dodds@talis.com>
- Cc: Paul Houle <ontology2@gmail.com>, public-lod <public-lod@w3.org>
Leigh, Do you think that http://www.w3.org/2004/03/trix/rdfg-1/ is sufficient for describing the relationships between graphs (for these purposes) and if not, what do you think needs adding? Jeni On 18 Jan 2010, at 19:20, Leigh Dodds wrote: > Hi Paul, > > 2010/1/18 Paul Houle <ontology2@gmail.com>: >> For a while I've been struggling with a number of practical >> problems working >> in RDF. Some of these addressed by Named Graphs as they currently >> exists, >> but others aren't. > > Looks to me like you need Named Graphs plus a mechanism to describe > combinations of graphs. > >> Over the weekend I had an idea for something that I think is highly >> expressive but also can be implemented efficiently. >> The idea is that the context of triple can be, not a name, but a >> collection of tags that work like tags on delicious, flickr, >> etc. Tags >> are going to be namespaced like RDF properties, of course, but >> they could >> have meanings like: >> #ImportedFromDBpedia3.3 >> #StoredInPhysicalPartition7 >> #ConfidentialSecurityLevel >> #NotTrue >> #InTheStarTrekUniverse >> #UsedInProjectX >> #UsedInProjectY >> #VerifiedToBeTrue >> #HypothesisToBeTested >> Individually I call these "Context Tags", and the set of them that >> is >> associated with a triple is a "Context Set". > > I see all of those as being Named Graphs. > >> Now, named graphs can be composed from boolean combination of >> tags, such >> as >> AND(#ImportedFromDbPedia3.3,#InTheStarTrekUniverse) >> NOT(#NotTrue) >> AND >> (NOT(#ConfidentialSecurityLevel),OR(#UsedInProjectX,#UsedInProjectY)) > > ...and these as more Named Graphs, or at least graphs that are derived > from those in the underlying data store. I tend to refer to these as > "synthetic graphs". Most SPARQL implementations have the concept of at > least one synthetic graph: the union of all Named Graphs in the > system. But as I alluded to in a recent posting [1], there are many > other ways that these graphs could be derived. Rather than building > them into the implementation, they could be described and using a > simple domain specific language. So I think Named Graphs plus graph > algebra gives you much of what you want. > > Cheers, > > L. > > [1]. http://www.ldodds.com/blog/2009/11/managing-rdf-using-named-graphs/ > > > -- > Leigh Dodds > Programme Manager, Talis Platform > Talis > leigh.dodds@talis.com > http://www.talis.com > > -- Jeni Tennison http://www.jenitennison.com
Received on Monday, 18 January 2010 19:57:16 UTC