The use of odbcinst.ini, odbc.ini or the ODBC configuration registry is optional for the ODBC CLI. An application can invoke SQLDriverConnect() and specify a connection string that omits an ODBC Data Source (DSN) specification.

If the connection string has sufficient information to connect to the database, the location and name of the ODBC driver library are automatically determined. The use of the iiodbcadmin utility (UNIX, Linux, and VMS) or Microsoft ODBC Administrator (Windows) is optional.