- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Tue, 7 Sep 2010 05:00:38 +0100
- To: Juan Sequeda <juanfederico@gmail.com>
- Cc: "Eric Prud'hommeaux" <eric@w3.org>, Michael Hausenblas <michael.hausenblas@deri.org>, RDB2RDF WG <public-rdb2rdf-wg@w3.org>
On 7 Sep 2010, at 04:43, Juan Sequeda wrote: > On Mon, Sep 6, 2010 at 10:31 PM, Richard Cyganiak > <richard@cyganiak.de>wrote: >> So there are at least TWO DISTINCT AUDIENCES for the direct mapping >> spec: >> >> 1. RDB2RDF vendors who implement R2RML engines and want to equip >> their >> systems with functionality similar to D2R's "generate-mapping" >> script, which >> generates a simple canonical R2RML file for a given database, with >> the >> intent of allowing further customization of the R2RML file by the >> user. >> >> 2. RDB2RDF vendors who implement RIF-based engines (or engines >> based on any >> other RDF-to-RDF transformation language). Users of these engines >> will write >> RIF rules that transform the direct graph into a custom graph. >> Users and >> vendors of these systems don't need the R2RML language. > > Great clarification and +1 on everything. > > Given that we are clear that there are two audience, the only thing > I'm > saying is that if we are going to write a document on the Direct > Mapping, > which one of the audiences is expecting to see a R2RML file... we > need to > have a R2RML syntax before we have a Direct Mapping document ready. Again, the “RIF-friendly audience” in 2. doesn't want to see R2RML, and is better served by a spec that simply describes the shape of the resulting direct graph. The “R2RML-friendly audience” in 1. would be reasonably well served by either approach -- describing the shape of the direct graph, or describing a canonical “direct R2RML file”. My preference would be to normatively specify the direct mapping as a direct graph. And have an informative appendix that describes an algorithm for creating the canonical direct R2RML file that produces the direct graph. > Hence my suggestion to put priority on syntax right now. I sort of agree. But I don't see a dependency of the direct mapping on R2RML. Richard
Received on Tuesday, 7 September 2010 04:01:14 UTC