client identifier api is not working for some of the names

[shamis]

for example MecIC63_BILL11_prod fails to be set as client identifier.
but its working for MecIC63_BILL12_prod

[c-bik]

To get the conection name list...

select s.sid, s.serial#, s.username, s.machine, s.program, s.CLIENT_IDENTIFIER
from gv$session s 
join gv$process p on p.addr = s.paddr 
    and p.inst_id = s.inst_id 
    where s.type != 'BACKGROUND' 
order by 3,4,5