Returns a Ingres II link resource on success, or FALSE on failure.
ingres_connect() opens a connection with the Ingres database designated by database, which follows the syntax [node_id::]dbname[/svr_class].
If some parameters are missing, ingres_connect() uses the values in php.ini for ingres.default_database, ingres.default_user, and ingres.default_password.
The connection is closed when the script ends or when ingres_close() is called on this link.
All the other ingres functions use the last opened link as a default, so you need to store the returned value only if you use more than one link at a time.
See also ingres_pconnect() and ingres_close().