OpenESQL is an integrated preprocessor that enables you to use Embedded SQL in your COBOL applications to access ODBC-enabled data sources.
Unlike separate preprocessors, OpenESQL is controlled by specifying the SQL directive when you compile your application.
Use OpenESQL if your application is designed to use different relational database systems or you are unsure which relational database system you may be using in the future.
For details of OpenESQL, see the chapter OpenESQL.
Oracle
If you are using an Oracle database and compile with the SQL directive TARGETDB set to ORACLEOCI then, at run time, the application will make OCI calls rather than ODBC calls. This means that the deployed application will not require an ODBC driver. For more details, see the section Oracle OCI Support in the chapter OpenESQL.