Problem processes:
1. Query by logging in directly to the host:
SQL> select * from nls_session_parameters where parameter = 'NLS_DATE_FORMAT';

PARAMETER VALUE
------------------------------ ----------------------------------------
NLS_DATE_FORMAT DD-MON-RR

************************************************


2. Set the NLS_DATE_FORMAT in init.ora:
NLS_DATE_FORMAT=DD/MM/YY

************************************************


3. Shutdown and Startup DB (Oracle 8.1.7).


4. Query by logging in directly to the host (again):
SQL> select * from nls_session_parameters where parameter = 'NLS_DATE_FORMAT';

PARAMETER VALUE
------------------------------ ----------------------------------------
NLS_DATE_FORMAT DD/MM/YY

************************************************


5. Run PL/SQL code that containing the SQL statement as the 1st and 4th via a web browser (served by Oracle iAS):

-----------------
NLS Session is
-----------------
Parameters Values
------------------------ ------------------
NLS_DATE_FORMAT DD MON RRRR

************************************************

Questions:
1. Why is NLS_DATE_FORMAT = 'DD MON RRRR'?
It should be NLS_DATE_FORMAT = 'DD/MM/YY' or not?

2. If Oracle iAS can specify the NLS session parameter, how can I do?
(I would not like to specify its from my code as using DBMS_SESSION.SET_NLS or other)

PS. I know where I can set NLS parameter at SESSION and SYSTEM level but I'm confused why NLS_DATE_FORMAT='DD MON RRRR' was returned by Oracle iAS that I never set the specific NLS paramter on the server. --by default NLS_DATE_FORMAT is 'DD-MON-RR' right?