PostgreSQL™ is an extensible database system. You can add your own functions to the server, which can then be called from queries, or even add your own data types. As these are facilities unique to PostgreSQL™, we support them from Java, with a set of extension APIs. Some features within the core of the standard driver actually use these extensions to implement Large Objects, etc.

Connection db = Driver.getConnection(url, username, password);
// ...
// later on
Fastpath fp = ((org.postgresql.PGConnection)db).getFastpathAPI();