- From: Gregory Williams <greg@evilfunhouse.com>
- Date: Mon, 28 Sep 2009 12:06:34 -0400
- To: Steve Harris <steve.harris@garlik.com>
- Cc: "public-rdf-dawg@w3.org Group" <public-rdf-dawg@w3.org>
On Sep 26, 2009, at 4:36 AM, Steve Harris wrote: >> So, in a quad store, you will describe each graph separately using >> voiD ? >> Won't it be too much information in the SD, e.g. if I have 1 >> million RDF files in my store, will have 1 million of voiD >> descriptions in the SD. > > Right, the FOAF store that backs http://foaf.qdos.com/ for example > has around 2 million graphs in it, and we would obviously like to be > able to describe its contents in a standard manner. We've talked about having both a way to embed the dataset description in the SD document and also a way to link to a URL where the dataset description can be retrieved. Would that satisfy your needs here? > Also, at the risk of sounding like a broken record :) it's critical > that there be a way to talk about the endpoint using relative URIs > or some similar trick so that the software emitting the descriptions > is not required to know the endpoint URI that the client is > connected to. > > Descriptions using <> as a subject are fine, but other things will > be problematic. I'm not sure what it is that you're referring to as I thought everything that's been proposed regarding the vocabulary so far is in line with your relative URI requirement. >> So >> >> <endpoint> sd:datasetDescription [ >> sd:defaultGraph [ >> sd:graphName <graph-name> ; >> sd:graphDescription <void-dataset-for-default-graph> ; >> ] . >> sd:namedGraph [ >> sd:graphName <graph-name> ; >> sd:graphDescription <void-dataset-for-named-graph> ; >> ] . >> ] . > > Let's not bake Void into SPARQL. It's sufficient to say that it > should be an RDF description, the exact vocabulary can be left open. Yeah, agreed. The idea was never to bake voiD into the spec, but to think of it as a possible best practice to use for describing the datasets (and it makes examples easier to discuss since we've already got a vocabulary that people know). >> while I'd think a simple way would be >> >> <endpoint> sd:datasetDescription <void-dataset-for-dataset> ; >> sd:defaultGraph <graph-name> ; >> sd:namedGraph <graph-name> . > > That would be more palatable, but if it's possible for the client to > request a description there needs to be some way for the client to > request the description of a specific graph. How about the two variants (embedded and linked) like so: sd:namedGraph [ sd:graphName <graph-name> ; sd:graphDescription <void-dataset-for-named-graph> ; ] . (this is example from before), and: sd:namedGraph [ sd:graphName <graph-name> ; sd:graphDescriptionURL <document-url-with-void-dataset-for-named- graph> ; ] . It's not quite as simple as just "<> sd:namedGraph <graph-name>", but it keeps the actual dataset description out of service description document while giving you a place to go get it. thanks, .greg
Received on Monday, 28 September 2009 16:07:15 UTC