Specify NLS-Settings during Oracle installation under Windows

Since 9i dbnewid utility (nid) can be used to change database name (and DBID if required). If database name being changed only then resetlogs is not required:

• 1 startup database in mount mode

  shutdown immediate
  startup mount
  

• 2 run nid to change database name:

  nid target=sys/syspassword@dbtns dbname=newname setname=YES
  

• 3 shutdown and start database in mount mode:

  shutdown immediate
  startup mount
  

• 4 change db_name in spfile (or in pfile editing the file):

  alter system set db_name=newname scope=spfile;
  

• 5 recreate password file:

  orapwd file=orapwnewname password=syspassword
  

• 6 startup the database

  startup
  

• 7 post rename steps:

  change SID in listener.ora
  correct tnsnames.ora
  remove old trace directories
  change /etc/oratab (UNIX) or rename windows service using oradim
  

There is no simple way to achieve this. You can either do it by tracing the session or by using a login trigger. Here's an example of how to do it using a DB login trigger.

Logging table:

create table nls_session_parameters_log
(
    inserted_date    date,
    sid              number,
    username         varchar2(128),
    parameter        varchar2(30),
    value            varchar2(40)
);

Public grant and synonym:

grant insert on nls_session_parameters_log to public;

create public synonym nls_session_parameters_log for sys.nls_session_parameters_log;

Database login trigger:

create or replace trigger nls_log_dbtrig after logon on database
begin
  if user in ('PHIL') then
    insert into nls_session_parameters_log
    select sysdate, (select sys_context('USERENV','SID') from dual), (select user from dual),parameter, value
    from nls_session_parameters;
  end if;

  exception
    when others then 
      null;
end;
/

Test:

SQL> conn phil/phil
Connected.
SQL> select count(*) from nls_session_parameters_log;

  COUNT(*)
----------
        17

SQL>

Obviously you'd be better off putting the table in an appropriate schema and granting on a per-user basis.

If you need help with another approach (session tracing), let me know.