Assume a Sales table with range partition and Customer table with partitions. Both tables have the same degree of parallelism and are particioned the same way on the join column (cust_id). Assume the query Select num(sales_amount) from SALES.s CUSTOMER.c Where s_cust_id = c.cust_id. In this case the large join is divided into multiple smaller joins. Each joins a pair of partitions in parallel.