Please do #8

Consider the following relational schema Product(maker, model, type) PC(model, speed, ram, hd, price) Laptop(model, speed, ram, hd, screen, price) . Printer(model, color, type, price) Write the SQL statement and draw the optimized relational algebra query execution tree for each of the following queries (10 points/SQL 10 points/query tree) 1. What makers produce Laptops with screen larger than 15'' that are cheaper than $1,000? 2. What makers produce PCs or Laptops, but do not produce Printers? 3. How many makers produce each type of product? 4. For each maker who produces PCs with more than 4 GB of ram, find the average price of these PCs (with more than 4 GB of RAM). 5. For all the makers that produce PCs, Laptops, and Printers, find the minimum price of a package that includes a PC, a Laptop, and a Printer. 6. Out of all the makers that produce PCs, find the cheapest Laptop sold by them. 7. Find the maker that sells the most expensive PC and also sells Printers. 8. How many makers produce PCs with speed larger than 2.0, Laptops with hd larger than 250 GB, and laser printers? 9. We want to rate the value of each PC. The score is computed as the sum of three terms: the score of the speed; the score of the ram; and the score of the hd. Each of these is computed as the ratio between the attribute (i.e., speed, ram, or hd) and the price. List the PCs and their score in decreasing order of the score. 10. Find the makers that produce at least 5 different products out of which there is at least one product of each type (i.e., PC, Laptop, and Printer)