EXTRA CREDITS PROBLEMS

FROM HW1 

Extra Credit 1

 

5.8.

Specify the following views in SQL on the COMPANY database schema

shown in Figure 3.5.

 

a. A view that has the department name, manager name, and manager

salary for every department.

 

b. A view that has the employee name, supervisor name, and employee

salary for each employee who works in the ‘Research’ department.

 

c. A view that has the project name, controlling department name, number

of employees, and total hours worked per week on the project for each

project.

 

d. A view that has the project name, controlling department name, number

of employees, and total hours worked per week on the project for each

project with more than one employee working on it.

 

 

 

15.28. Consider the relation R, which has attributes that hold schedules of courses

and sections at a university; R = {Course_no, Sec_no, Offering_dept,

Credit_hours, Course_level, Instructor_ssn, Semester, Year, Days_hours, Room_no,

No_of_students}. Suppose that the following functional dependencies hold

on R:

 

{Course_no} → {Offering_dept, Credit_hours, Course_level}

{Course_no, Sec_no, Semester, Year} → {Days_hours, Room_no,

No_of_students, Instructor_ssn}

{Room_no, Days_hours, Semester, Year} → {Instructor_ssn, Course_no,

Sec_no}

 

Try to determine which sets of attributes form keys of R. How would you

normalize this relation?

 

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%)

 

all figures u need u will find in the book 

 

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 assumptions, if you

make any.)