Introduction to Database Systems

3. Suppose a database schema consists of four relations whose schemas are: Product (maker, model, type) PC (model, speed, ram, hd, price) Laptop (model, speed, ram, hd, screen, price) Printer (model, color, type, price) The Product relation gives the manufacturer, model number, and type (PC, laptop, or printer) of various products. We assume for convenience that model numbers are unique over all manufacturers and product types (which is not realistic, but just an assumption for this exercise) The PC relation gives for each model number that is a PC the speed of the processor in gigahertz, the amount of RAM in megabytes, the size of the hard disk in gigabytes, and the price. The Laptop relation is similar - except that the screen size (in inches) is included The Printer relation records for each printer model whether the printer produces color output (true, if so), the process type (laser or ink-jet), and the price. Write the following declarations using the data-definition sublanguage of SQL (See section 2.3) (a) A suitable schema for the relation Product (b) A suitable schema for the relation PC c)A suitable relation for the relation Printer