System Requirements for the Oracle OCI driver

The Oracle OCI driver is also called the thick driver because of the extensive native code it uses to communicate with the database. OCI is written in C; all of its Java calls use JNI to direct the calls to the C layer. The C layer communicates with the database and returns the results to the Java layer.

The library to map the Java calls to C calls is installed with the Oracle client’s installation. To enable monitoring and recovery persistence with OCI, you must install the Oracle client software.