Call Interface:The application program interface (API) with which to access the data source. Some databases may be accessed using native APIs, some use ODBC, and some work both ways.
Connection types are:
Available connection types are ODBC, DB2 CLI, DB2 CLI (Unicode), and XML.
Most physical schema imports are performed using an ODBC connection type.
Native database gateways for schema import are supported for only DB2 (using DB2 CLI or DB2 CLI Unicode) and XML connection types.