“…The works from [9,10,11] provided a classification covering aspects such as the existence of an initial ontology, its application in reverse engineering, automation level, and others. Notably, the approaches [12,13,3,14,15,16,6,17,18,19,5,20] aim to convert relational data models to ontologies, by providing mapping rules that translate the elements of a database schema into concepts and relationships of an ontology. The W3C RDB2RDF Working Group provides as well a survey [21] of different approaches of mapping relational databases to ontologies, including the definition of a reference architecture to compare them.…”