Optimizing the Oracle Query Optimizer
20-Oct-10The Oracle Query Optimizer does a great job in rewriting Queries. For example the nested subquery in SELECT C.cust_last_name, C.country_id FROM customers C WHERE EXISTS (SELECT 1 FROM sales S WHERE S.quantity_sold > 1000 AND S.cust_id = C.cust_id);SELECT C.cust_last_name, C.country_id FROM customers C WHERE EXISTS (SELECT 1 FROM sales S WHERE S.quantity_sold > 1000 and […]