Consider the following relational database which consists of the 4 following relations: 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 and type (PC, Laptop, or printer). We assume for convenience that model numbers are unique over all manufacturers and product types. The PC relation gives for each model number the speed of the processor(in gigahertz), the amount of RAM(in megabytes) and the size of the hard disk (in gigabytes), and the price. The Laptop relation is similar, except that the scorch size is also included. The Printer relation records for each printer model whether the printer produces color output or not, the process type (laser or ink-jet), and the price. 1) Define a suitable schema for each relation.
2) Draw the Crow foot representation of your database.
3) Write expressions of relational algebra for the following queries and draw the query trees for each:
a. What PC models have a speed of at least 3. 00
b. What the model numbers of all color printers
c. Which manufacturer make laptops with at least 100 GB
d. Find the model and price of all products (of any type) made by manufacturer "B"
e. Find the manufacturers that sell laptops but not PC.