Analytical Functions in Oracle

http://docs.oracle.com/cd/E11882_01/server.112/e41084/functions004.htm#SQLRF06174

if i explain this with a simple example .. lets say we have a to take a data set like this..

"select  sum(order_amt) from t01_orders group by order_no "


this will certainly  return the sum of each order amount . but what if want to show other details like customer name and all.. you can not add that column to group by clause.


"select sum(order_amt) over(partition by order_no) , * from t01_orders"


simple like that ... :)