You need the monetdb-jdbc-2.15.jar file, because that is the actual JDBC driver.

The jdbcclient.jar file is a simple JDBC client and the monetdb-mcl-1.11.jar is most likely a lower-level communication library.

If you use Maven in your project you can also find a maven'ized version of the JDBC driver JAR at https://clojars.org/monetdb/monetdb-jdbc.

Best of luck!

Best regards,

Dennis