You keep tnsnames.ora and change the sid to service name or keep sid if you like. Dick Goulet Senior Oracle DBA ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of sundar mahadevan Sent: Thursday, January 27, 2011 4:42 PM To: Oracle-L@xxxxxxxxxxxxx Subject: Do I need tnsnames.ora to connect to the DB with dynamic listener registration Hi All, Sorry about this basic question. I can understand how dynamic registration works but does dynamic listener service registration completely eliminate the use of tnsnames.ora or do i keep the tnsnames.ora and change the sid to service_name. Thanks in advance.