In the problem below, x and y are local application program values Read( ) and Write( ) fetch and stored the persistent values in a database, The database values are read / written by two different transactions. The time sequence of these operations is shown in the table below. You cannot change the time sequence. Take the initial values of x and y to be x = 4, y = 2. a) In this part the transactions are operating with isolation level READ UNCOMMITTED (no locks) Time | Transaction 1 Transaction 2 Read(y) y=y+5 Read(y) yy+ 10 3 Write(y) Read(x) 6. Read(x) X=x+ y: Write(y) 8. 10 Commit 11 Xx+y Write(y) Commit 12 13 For the execution order shown above, what are the final values of x and y? Answer: x=

A taxi company would like to provide an online service for customers to book a trip and for taxi drivers to check their upcoming trips. A database needs to be created to store customer data (name, address, email, telephone number) and trip information (pick up and drop off address and pick up time and date). Furthermore, your database should contain driver information (name and license plate). Each trip must be assigned to exactly one driver (and trips for a driver must not overlap). Customers who are not registered yet need to register (providing their address, phone number, email address, and credit card information). A registered customer should be able to book a trip, i.e. provide the pick-up address and time as well as the drop-off address via a graphical user interface. Customers should also be able to view their trips and cancel them if needed. All these operations are only possible after a customer signs in (which means they must be registered). Each new trip must be confirmed…