The API guide shows a connection parameter
isc_dpb_sys_user_name
which is separate from
isc_dpb_user_name
Can anyone tell me what this parameter does?

if isc_dpb_sys_user_name is supplied and no isc_dpb_user_name supplied a
correct password, connection is rejected
if isc_dpb_sys_user_name and isc_dpb_user_name is supplied with sysdba
password, connection is accepted.

Thanks
Alan