This is one of the key advantages of using the JRIO library rather than developing a new customized version of APIs to access data sets using JNI interfaces. As we described earlier, JNI-based solutions would not utilize zAAPs. Scenarios 6 through 9: DB2 access with different drivers The JDBC specification describes four different types of driver architectures to connect Java applications to databases. Among the four architectures, Type 2 and Type 4 drivers are the most commonly used in enterprise applications today. Type 2 drivers are written partly in the Java programming language and the rest is written in native code. The drivers use a native client library specific to the data source to which they connect. Type 4 drivers are written purely in Java and implement the network protocol for a specific data source. In this experiment, we developed a pair of Java programs for each driver type to get the estimate of potential zAAP utilization. The first program reads data stored in an existing database table using the SELECT operation. The second program deletes a set of tables, re-creates the table and populates the table with randomly generated data. The same set of programs is used every time, except for the driver type used for each experiment. Because of the architectural specification of the drivers, we expected almost full zAAP utilization with the Type 4 drivers and much less utilization with the Type 2 drivers.