Homework 1

This first homework is due on Tuesday October 8th. You will work alone on this homework -- You may however exchange your ideas with other students. You are encourage to work on this homework before the test (Tuesday October 1st).

Instructions: Follow the 'guidelines for assignments'. Be clear, understandable and precise in your explanations. The SQL code must be tested on matrix.

1. Mathematics Foundations

Let S ={a,b,c} and T={{},a}. Compute S x T.

Let S be the powerset of E and |E| = n. How many relations on S are there? Explain.

2. SQL

Exercises 2.4 and 2.5 on page 26.

Exercise 2.11 page 27.

3. Entity Relationship Diagram

Computer Sciences Department frequent fliers have been complaining to Dane County Airport Officials about the poor organization at the airport. As a result, the officials have decided that all information related to the airport should be organized using a DBMS, and you have been hired to design the database. Your first task is to organize the information about all the airplanes that are stationed and maintained at the airport. The relevant information is as follows:

* Every airplane has a registration number, and each airplane is of a specific model.

* The airport accomodates a number of airplane models, and each model is identified by a model number (e.g. DC-10) and has a capacity and a weight.

* A number of technicians work at the airport. You need to store the name, SSN, address, phone number, and salary of each technician.

* Each technician is an expert on one or more airplane model(s), and his/her expertise may overlap with that of the other technicians. This information about technicians must also be recorded.

* Traffic controllers must have an annual medical examination. For each traffic controller, you must record the date of most recent medical exam.

* All airport employees (including technicians) belong to a union. You must store the union membership number for each employee. Each employee is uniquely identified by the SSN.

* The airport has a number of tests that are used periodically to ensure that airplanes are still airworthy. Each test has a Federal Aviation Administration (FAA) test number, a name, and a maximum possible score.

* The FAA requires the airport to keep track each time that a given airplane is tested by a given technician using a given test. For each testing event, the information needed is the date, the number of hours the technician spent doing the test, and the score that airplane received on the test.

Draw an ER diagram for the airport database. Be sure to indicate the various attributes of each entity and their domains and relationship set; also specify the key and cardinality constraints for each relationship set. Specify any necessary overlap and covering constraints as well (in English).

Notes: - Please write your assumptions clearly, if any.

- You can draw your ERD by hand or use a tool. For example you can use MS word to draw ER diagrams using flowchart symbols. You can as well use SmartDraw to draw them. SmartDraw is free and easy to use (Please look on the web). If you use any other tool please provide the name and URL (if any).

- Be very clear when you add the cardinality constraints and show your work. Use the Chen notation.