About UTF8 ,Unicode, NVARCHAR2

Question

Hi,
I have a UTF8 database, converted all the data types to NVARCHAR2 AND NCHAR so I could store the Unicode characters. I have changed the program that reads the file using utilfile from fopen,get_line to fopen_nchar and get_line_nchar to make sure the program handles Unicode characters.
In one of the existing program in the where clause as well as assignments of strings to NVARCHAR2 variable should I prefix with N where N converts the characters into Unicode where columns Or variables are NVARCHAR2 OR NCHAR data types.
i.e.
In the where clause lets say status column of a table is STATUS NVARCHAR2(64) . In the where clause should I change from Stauts = 'valid' to status = N'valid' where N converts the characters into Unicode type explicitly instead of relying on oracle to implicitly convert ?
Please give your suggestions?
Thanks.
Vin.

Answer 1

All our columns are nvarchar2 in the UTF8 datbase. I have been told to use N in the select statement and in the the where clause just to be on the safe side so when a string is compared to NVARCHARR column it does explicit conversion instead of
depending on oracle to do implict conversion internally.
select * from tab
where status = N'testing'
What do you think about this adding N?