oracle Update comparing Varchar
问题 I have two tables: OrdHead: Order_no, CustOrd OrdItem: Item, Order_no, CustOrd Both the tables are joined using Order_No which is Alphanumeric.. I need to to update CustOrd (NUMBER) column of OrdItem with the same CustOrd number in OrdHead table using Order_no. What is the best way to do that ? Do I add any index to the tables? Currently I do it with the following query, but its taking alot of time just with 100,000 records. UPDATE ORDITEM A SET CUSTORD = (SELECT CUSTORD FROM ORDHEAD b WHERE