RETRO: A Framework for Semantics Preserving SQL-to-SPARQL Translation
There have been several attempts to make RDBMS and RDF stores inter-operate. The most popular one, D2RQ, has explored one direction, i.e., to look at RDBMS through RDF lenses. In this paper, the authors present RETRO, which investigates the reverse direction, i.e., to look at RDF through relational lenses. RETRO generates a relational schema from an RDF store, enabling a user to query RDF data using SQL. A significant advantage of this direction in-addition to interoperability is that it makes numerous relational tools developed over the past several decades, available to the RDF stores.