Oracle Class Library (OCL) provides native connectivity to the Oracle database server. OCL uses Oracle Call Interface (OCI) directly. OCI is low-level native application programming interface to access to Oracle. Using OCI in Oracle Class Library allows to create lightweight and fast applications working with Oracle. Oracle Class Library encapsulates OCI calls in high-level classes that allows to hide the complexity of using OCI directly and keep perfomance and all abilities of native routines. With OCL you can use the power and flexibility of SQL in your application programs without any restrictions.