DBI->connect("dbi:Oracle:$db_name:$db_host:$db_port", $db_user, $db_pass);

##</code><code>##

 db_name =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = db_host)(PORT = db_port))
)
(CONNECT_DATA =
(SERVICE_NAME = db_name)
)
)