Composite Primary key or 1 primary key column with all values

Which is faster? 6 columns or 1 column with all keys. Speed is the only issue.
col1 varchar(3) = aaa
col2 varchar(3) =bbb
col3 date =12/31/01

col4 number(1) =1
col5 number(1) = 0
col6 number(1) =1

OR

one_column varchar2(20) = "aaabbb12312001101"

I have a few tables with the same primary key. For perfomce only. does anyone know? MultiMillion row table. Received on Fri Aug 09 2002 - 20:44:43 CDT