NOTE: DO NOT REMOVE THIS EXAM PAPER FROM THE EXAM VENUE

Transcription

1 Exams, Awards & Graduations NOTE: DO NOT REMOVE THIS EXAM PAPER FROM THE EXAM VENUE EXAM COVER SHEET EXAMINATION DETAILS Course Code/s: ISYS1055/1057 Course Name/s: Database Concepts Date of Exam: Sample Exam Time of Exam: Sample Exam Duration of Exam: 2:15 Total no. of pages (incl. cover sheet): 6 ALLOWABLE MATERIALS AND INSTRUCTIONS TO CANDIDATES: 1. Write your full name and student number on each examination booklet together with the number of examination books used. Students must not write during reading time. 2. The examination paper contains 4 questions. 3. Answer all questions. 4. This is a CLOSED BOOK exam. You may not refer to any written or printed materials during the examination. 5. You are not allowed to use any electronic devices, such as calculators or personal organisers. Mobile phones must be switched off. 6. This paper accounts for 50% of your total assessment in this course and will be marked out of 120 marks (or 1 mark per minute). 7. If you need to make any assumptions then state them clearly in your answer. Any such assumptions must be sensible in the context of the question. 8. You are not allowed to take this exam paper away from the exam venue. Place it inside your answer booklet.

2 ISYS1055/ 1057 Sample Examination, Sem 2, 2018 page 2 of 6 Question 1: Relational Database System Concepts (15 Marks) This question is based on the company database schema used in the first assignment (courtesy of Elmasri & Navathe s Fundamentals of Database Systems text book.) The schema is given below. A sample database instance is attached to the end of the exam paper. EMPLOYEE(SSN, FNAME, MINIT, LNAME, BDATE, ADDRESS, SEX, SALARY, SUPER SSN*, DNO*) DEPARTMENT(DNUMBER, DNAME, MGR SSN*, MGR START DATE) DEPT LOCATIONS(DNUMBER*, DLOCATION) WORKS ON(ESSN*, PNO*, HOURS) PROJECT(PNUMBER, PNAME, PLOCATION, DNUM*) DEPENDENT(ESSN*, DEPENDENT NAME, SEX, BDATE, RELATIONSHIP) Suppose that each of the following update operations is applied directly to the database instance shown on Page 6. (Note that all the updates are to be applied to the original database instance i.e. ignore the effects of previous updates when you consider the next update). List all integrity constraints violated by each operation. If the operation does not violate any constraints, indicate as no violations. For each and every violation, explain why such violation occurred and actions you can take to make sure that the operation does not violate any integrity constraints. 1.1 Insert < Robert, F, Scott, , 21-JUN-42, 2365 Newcastle Rd, Bellaire, TX, M, 58000, , 1 > into EMPLOYEE. 1.2 Insert < ProductA, 3, Bellaire, 2> into PROJECT. 1.3 Insert <Production, 4, , 01-OCT-88 > into DEPARTMENT. 1.4 Insert < , null, 40.0 > into WORKS ON. 1.5 Insert < , John, M, 12-DEC-60, SPOUSE > into DEPENDENT. continued...

3 ISYS1055/ 1057 Sample Examination, Sem 2, 2018 page 3 of 6 Question 2: Conceptual Modeling (30 Marks) Consider the following description, involving cars, car models, car manufacturers, and car dealerships. Description: Car Manufacturers are companies that build cars and they have attributes such as name, headquarters address, etc. Cars have attributes such as make (e.g., Ford, Holden, Chrysler), country of origin, etc. Car models have attributes such as model name, first year of manufacturing, weight, engine capacity, seating capacity, number of doors, kind of car (e.g., sedan, UTE, wagon), etc. Model names are unique within a manufacturer, but not unique among the entire collection of models (e.g. Holden Gemini and Isuzu Gemini can co-exist). A dealership sells cars. It has a name, address, and telephone numbers (typically more than one.) A manufacturer may make several different makes and models of cars (as, for example, the manufacturer Toyota manufactures makes such as Toyota and Lexus. Furthermore, Toyotas have different models such as Camry and Corolla). A car is made by only one manufacturer. There are two types of dealerships authorised dealerships, and general dealerships. A general dealership can sell cars from several different manufacturers but does not have to sell all the models from a single manufacturer. For example, Honest Car Dealers in Clayton sells Toyota Camrys and Lexus LX350s from manufacturer Toyota, and Ford Falcons from manufacturer Ford, but it doesn t sell Toyota Corollas that are also made by Toyota. An authorised dealership sells cars from one manufacturer only. They sell all makes and models of that particular manufacturer. For example, Canon Toyota Dealers sells all models of cars manufactured by Toyota Company. Task: Using UML notation, draw an entity-relationship diagram to accurately represent the above description. You must clearly denote cardinality and participation constraints of each relationship and participation constraints of specialisations. Write down any assumptions you make, if they are not explicitly described here. Your assumptions should be sensible in this context and should not contradict with anything given in the above description. To make your ER diagram neat and tidy, you are not required to show the attributes of the entities and relationships within the diagram. List them separately, outlining which attributes belong to which entity. Make sure you clearly identify primary keys of the strong entities and partial keys of weak entities. [35 Marks in Total] continued...

4 ISYS1055/ 1057 Sample Examination, Sem 2, 2018 page 4 of 6 Question 3: Relational Design (25 Marks) The ABC Company customer management system has the following requirements: Each customer has a unique customer ID; An order has a unique order No, and also has an order date; A customer can have several orders. But an order belongs to only one customer; On an order there can be several products and their quantities. Below is an initial design which includes all information (attributes) that needs to be kept in the database: Customer(custID, custname, orderno) Order(orderNo, order_date, product_code, quantity) Answer the following questions based the given description. 1. List all likely non-trivial and non-redundant FDs. [6 Marks] 2. Find the primary key for Customer and Order. Explain your answer. [6 Marks] 3. What the highest normal form is this relation in? Explain the reasons why it does not meet the requirements of the next normal form. You are not required to provide an explanation if a relation is in 3NF. [6 Marks] 4. If any of the relations is not in 3NF, decompose into a set of 3NF relations. [7 Marks] continued...

5 ISYS1055/ 1057 Sample Examination, Sem 2, 2018 page 5 of 6 Question 3: SQL (50 Marks) This question is based on the company database schema used in the first assignment (courtesy of Elmasri & Navathe s Fundamentals of Database Systems text book.) The schema is given below. A sample database instance is attached to the end of the exam paper. EMPLOYEE(SSN, FNAME, MINIT, LNAME, BDATE, ADDRESS, SEX, SALARY, SUPER SSN*, DNO*) DEPARTMENT(DNUMBER, DNAME, MGR SSN*, MGR START DATE) DEPT LOCATIONS(DNUMBER*, DLOCATION) WORKS ON(ESSN*, PNO*, HOURS) PROJECT(PNUMBER, PNAME, PLOCATION, DNUM*) DEPENDENT(ESSN*, DEPENDENT NAME, SEX, BDATE, RELATIONSHIP) 3.1 Write an SQL query to retrieve the name of dependents of John B Smith. [6 Marks] 3.2 The following query has been developed to retrieve full names of all employees who have two or more dependents. It is incorrect. Rewrite this query to produce the expected outcome. SELECT fname,minit,lname FROM employee,dependent WHERE employee.ssn = dependent.essn AND COUNT(*) >= 2; [10 Marks] 3.3 Write an SQL query to display the full name of employees working on the same projects as John B Smith. You must use a nested query in your answer. [8 Marks] 3.4 Write an SQL query to fulfill this requirement: For each employee, display the full name and the total number of hours working on projects. If there are employees who are not working on any projects, their names should be displayed with 0 hours. [8 Marks] 3.5 It is required to find the full name of the longest serving manager. Write down an SQL query to produce that output. [6 Marks] 3.6 Write an SQL statement to retrieve the name of departments located in Houston. [6 Marks] 3.7 Write an SQL statement to retrieve the full name of department managers who earn more than $ and less than $ [6 Marks] End of Paper

6 ISYS1055/ 1057 Sample Examination, Sem 2, 2018 page 6 of 6