R2RML-based access and querying to relational clinical data with morph-RDB

Semantic interoperability is essential when carrying out post-genomic clinical trials where several institutions collaborate, since researchers and developers need to have an integrated view and access to heterogeneous data sources. In this paper we present a solution that uses an ontology based on the HL7 v3 Reference Information Model and a set of R2RML mappings that relate this ontology to an underlying relational database implementation, and where morph-RDB is used to expose a virtual SPARQL endpoint over the data. In previous efforts with other existing RDB2RDF systems we had not been able to work with live databases. Now we can issue SPARQL queries to the underlying relational data with acceptable performance, in general.%with a similar performance to having used the corresponding SQL native queries