Some quick testing with JMeter showed me that under some serious load on my webapp (100 Tomcat threads, 300 queries a second, some with multi-table joins), the Oracle 11 JDBC driver performs much better than the Oracle 9 JDBC driver, even against a 9i database.  This isn’t a set of benchmarking results, which I know Oracle doesn’t like anyone to talk about, it’s just comparing old vs new Oracle drivers.

The takeaway, go get an updated JDBC driver, now!  Even if you’re running against Oracle 9i or 10g for the database, the new driver will give you a performance boost.  For free!