Here is what worked for me: Start up MS SQL server and run a tool that can be compiled from sources at Codeproject. Transfer the resulting SQLITE3 database to the Mac where it can be accessed by R via the RSQLite library. Many thanks to Liron Levi and his patient help with tables having more than 1000 columns!
I am in the process of setting up a graphical ER management tool while the native ODBC driver still seem to have some problems. Any workaround is greatly appreciated.