Rownum In Oracle

Example :- To Display First  5 top Record in  Oracle ,You can use Rownum Command because oracle does not support Top


select employee_id,last_name
from employees
where rownum <=5
/


EMPLOYEE_ID LAST_NAME
----------- -----------------------
        198 OConnell
        199 Grant
        200 Whalen
        201 Hartstein
        202 Fay