We have developed a system that can process queries to RDF views of large relational databases. This provides very flexible views of wrapped databases that can be queried using either RDQL or SQL. Query processing over such views is challenging because their naive implementation becomes very complex. This makes it critical to optimize not only data access time but also the time to perform the query optimization itself. We have developed query processing techniques based on partial evaluation of query expressions as a way to enable execution of real-world queries to RDF views of relational databases.