I tend to think FileMaker is the best box of bits and bytes ever assembled. While its ODBC capabilities are adequate for doing a PUT as well as a GET, thereby functioning as a front end, it ain't fast. (JDBC is somewhat faster, if I recall correctly).
We briefly connected parts of a sprawling FileMaker system to an Oracle mess in this fashion, on a LAN with decent pipes, but it was sufficiently miserable for us that we gave up and exported as tab-delimited text and imported that into Oracle instead.
This was Fm6 architecture, it may have improved under Fm7-Fm8.