A gateway alias connection is similar to an Ingres database connection except that instead of the database name, a database alias is specified. Unlike Ingres, the server class option is mandatory when connecting using the gateway. The server class indicates the type of target DBMS being used. An alias looks (and is used) like a standard Ingres database name. A gateway alias is, in fact, a look-up mechanism to access target DBMS-specific connection information. The target DBMS often uses a different database naming convention that is incompatible with Ingres naming conventions.

The host database name with the host database username and password if provided is stored in the config.dat configuration file. The alias information is used to establish a connection to the host DBMS. Be aware that specifying the host database username and password in the gateway alias has security implications, as the information is stored in plain text.

Gateway aliases are created and maintained on all platforms using the command line tool, gwalias (Gateway Alias Utility).

Windows users can also use the GUI-based utility, gwaliasw (Gateway Alias Utility shortcut) to create, update and delete gateway alias definitions.