Big table - very big table join - forum topic by debu_ju

Hi All,
I have a performance issue with a query. Below is the sample query where sales table does not have any index on cust_ky, but rep has cust_ky as a NUPI. Volume of rep is about 13 million and sales is 100 million.
 
select r.rep_nm, s.qty
from sales s join rep r on s.cust_ky = r.cust_ky
 
1. What should be the ideal join strategy for this case? 
2. Is a NUSI on sales.cust_ky going to help? 
 
Thanks
Debu