Describe a smart card.
What will be an ideal response?
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Finding an element in a balanced binary search tree that contains n elements requires _____________________ comparisons.
O(1) b) O(n) c) O(2 n ) d) O(log 2 n) e) none of the above
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.)
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%)
Use the following schema for this problem:
Sailors(sid: integer, sname: string, rating: integer, age: real) key - sid Boats(bid: integer, bname: string, color: string) key - bid Reserves(sid: integer, bid: integer, day: date) key - sid, bid, day(a) Output the names of all sailors who have only rented a single boat (although they might have rented that boat several times). (b) Define a view giving the reservation history of junior sailors (sailors under 16 years old). For each reservation that a junior sailor has made, the view has a row giving the sailor's name and Id, the boat name and Id, and the day the boat was reserved. (c) Using the view of (10b), give a SELECT statement that returns the name of each sailor, the name of the boat that that sailor has rented, and the number of times the sailor has rented that boat.
When information is arranged as records in rows and fields in columns, you can ________ the data
A) store B) update C) release D) query