Database Systems 6th Edition by Ramez Elmasri, Shamkant B. Navathe

تمرين 14

Consider the following relations for an order-processing application database at ABC, Inc.
ORDER (O#, Odate, Cust#, Total_amount)
ORDER-ITEM (O#, I#, Qty_ordered, Total_price, Discount%)
Assume that each item has a different discount. The Total_price refers to one item, Odate is the date on which the order was placed, and the Total_amount is the amount of the order. If we apply a natural join on the relations Order-Item and Order in this database, what does the resulting relation schema look like? What will be its key? Show the FDs in this resulting relation. Is it in 2NF? Is it in 3NF? Why or why not? (State any assumptions you make.)