- From: ashok malhotra <ashok.malhotra@oracle.com>
- Date: Fri, 30 May 2008 09:24:40 -0700
- To: Paul Tyson <phtyson@sbcglobal.net>
- CC: "public-xg-rdb2rdf@w3.org >> public-xg-rdb2rdf" <public-xg-rdb2rdf@w3.org>
Paul: Would you be able to present to the XG on June 13? The telcons are at 11AM US Eastern time. It would be helpful is you could send a pointer to your presentation ahead of time. All the best, Ashok Paul Tyson wrote: > > I am not a member of the XG, but have been following the discussions. > It is apparent that there are any number of ways to expose RDB data as > RDF, but not so apparent that there are any aspects of these > approaches that could or should be standardized. > > I suggested in an earlier note > (http://lists.w3.org/Archives/Public/public-xg-rdb2rdf/2008Mar/0029.html) > that one aspect of standardization that would advance the state of the > art is an RDFS or OWL formulation of the relational model itself. Any > method of getting RDB data to RDF has to deal with the relational > model either explicitly or implicitly. By making an explicit model of > RDB in RDF, we at least provide a reference point for all > implementations. > > Here is a rough cut straw man proposal. It has several defects, and > raises many questions. I would like to submit this to the XG for > discussion on at least 3 topics: > 1) the validity and usefulness of the schema itself (or any such > schema); > 2) possible use in automated SQL-SPARQL rewriting (2-way); > 3) possible use as an intermediate format between RDB and > domain-specific ontologies. > > @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . > @prefix rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns# . > @prefix rdb: http://www.w3.org/xg-rdb2rdf/rdb# . > > rdb:Relation a rdfs:Class . # a database table > rdb:relationName a rdf:Property ; # the table name > rdfs:domain rdb:Relation . > rdb:header a rdf:Property ; > rdfs:domain rdb:Relation ; > rdfs:range rdb:RelationHeader . > rdb:body a rdf:Property ; > rdfs:domain rdb:Relation ; > rdfs:range rdb:RelationBody . > rdb:RelationHeader a rdfs:Bag . # of TypeDefinitions > rdb:TypeDefinition a rdfs:Class . > rdb:typeName a rdf:Property ; # of a TypeDefinition or TypedValue > rdfs:range rdb:TypeDefinition ; > rdfs:range rdb:TypedValue . > rdb:underlyingType a rdf:Property ; # of a TypeDefinition > rdfs:range rdb:TypeDefinition . > rdb:primaryKey a rdf:Property ; # boolean > rdfs:range rdb:TypeDefinition . > rdb:foreignKey a rdf:Property ; # reference to foreign typeName > rdfs:range rdb:TypeDefinition . > rdb:RelationBody a rdfs:Bag . # of Tuples > rdb:Tuple a rdfs:Bag . # of TypedValues > rdb:TypedValue a rdfs:Class . > rdb:value a rdf:Property ; # of a TypedValue > rdfs:range rdb:TypedValue; > >
Received on Friday, 30 May 2008 16:27:17 UTC