SQL & PL/SQL

Hi,

I have a unique problem - (no pun intended) - pls bare with me while I explain...

I have the following table (tbl_party) :

p_num VARCHAR2(30)
p_name VARCHAR2(100)
p_cert NUMBER
i_cat NUMBER
p_stat DATE

Test 1.
When I do a select count(distinct(p_num)) from tbl_party;
Return 6298 rows

Test 2.
When I do a select distinct(p_num) from tbl_party;
Return 6298 rows

Test 3.
When I do a select distinct(p_num), p_cert from tbl_party;
Return 6300 rows???

Can some1 pls enlighten me if there is a limitation on distinct/unique when using it on VARCHAR2??

Thanks in advance.

Jaco