Latest n rows of table - without a nested select

Hi,

   Within oracle SPL, I want to select 2 columns of the latest n rows of a table.
I currently do this with a nested select. For example to get columns a and b of the most recent single row of table a_journal:

           select a,b into p_a, p_b FROM
              (SELECT a, b, from a_journal
	      where (c = 'O' or c = 'A')
              order by system_date desc)
	  where rownum = 1;

Is there any way of doing this in a single select (i.e. not using a nested select)
Note: The table also contains a sequence (the tables primary key). Can this be used ?

Any help appreciated,
Peter Received on Mon Oct 24 2005 - 08:59:48 CDT