Oracle Proposal for R2RML Translation Tables

9 Translation Schemes (rr:TranslationScheme, rr:translationMap, rr:TranslationMap)

Sometimes the generated RDF terms produced by column-valued or template-valued term maps may be rather cryptic and user may want to translate them to different and usually more meaningful RDF terms. Such a translation scheme may require enumeration of the mapping pairs: (fromTerm, toTerm). This can be achieved in R2RML by associating one or more translation schemes with a term map. A translation scheme is a set of RDF term pairs. Each such mapping pair is specified as a translation map. A term map MAY be associated with one or more translation schemes, but the term-to-term mapping scheme represented by these translation schemes as a whole MUST be a bijection.

Consider the following database table that stores some proprietary code values for various cuisines:

CuisineCode
1
2
3

The following example object map translates the code values in the CuisineCode column to some (rather cryptic) IRIs:

   [] rr:predicate <http://chef.example.com/cuisineName> ;
      rr:objectMap [ rr:template "http://chef.example.com/cuisines/Code/{CuisineCode}" ; rr:termType rr:IRI ] .
    

To make the IRIs more meaningful, user may want to create the following translation scheme:

IRI_generated_by_object_map	translated_IRI
http://chef.example.com/cuisines/Code/1	http://chef.example.com/cuisines/indian
http://chef.example.com/cuisines/Code/2	http://chef.example.com/cuisines/thai
http://chef.example.com/cuisines/Code/3	http://chef.example.com/cuisines/italian

The above translation scheme may be included in an R2RML mapping document by associating a translation scheme with the relevant term map as follows:

 [] rr:column "cuisine";
     rr:translationScheme <http://chef.example.com/cuisines> .

 <http://chef.example.com/cuisines> rr:translationMap 
   [ rr:fromTerm <http://chef.example.com/cuisines/Code/1> ; 
     rr:toTerm <http://chef.example.com/cuisines/indian>
   ] ,

   [ rr:fromTerm <http://chef.example.com/cuisines/Code/2> ; 
     rr:toTerm <http://chef.example.com/cuisines/thai>
   ] ,

   [ rr:fromTerm <http://chef.example.com/cuisines/Code/3> ; 
     rr:toTerm <http://chef.example.com/cuisines/italian>
   ] .