bug/feature with upper function?

Hello All,

I am having a serious problem matching text using the upper() function
in postgres 7.2 (from developer rpms) on Redhat 7.2

How to replicate:

1. create a table of one column character(20)
2.insert words with all uppercase letters.
3. Try matching the word with "select * from table where
upper(columnname) = 'word'"

I get a result of zero every time.

db=# SELECT * from upp_test ;
uname
----------------------
KAT
KAT
KAT
KAT
KAT
(5 rows)

FEC=# SELECT * from upp_test where uname = 'KAT' ;
uname
----------------------
KAT
KAT
KAT
KAT
KAT
(5 rows)

db=# SELECT * from upp_test where upper(uname) = 'KAT' ;
uname
-------
(0 rows)

The reason I am worried about this is that I have a mix of upper and
lower case words in the real world coumn and I have not been getting
complete matches. Is this a bug?

Vincent