INF2603 October/November 2024

INF2603 October November 2024 ;100 % TRUSTED workings, Expert Solved, Explanations and Solutions. For assistance call or W.h.a.t.s.a.p.p us on ...(.+.2.5.4.7.7.9.5.4.0.1.3.2)........... QUESTION 1 [20 marks] Carefully select the most correct answer to each of the following questions. Please write down only the question number and corresponding to it put the correct option’s number (e.g. Qu. 11. (e)): For question 1 to 5: Indicate whether the statement is true or false. (2 marks each): 1. Overlapping subtypes are subtypes that contain nonunique subsets of the supertype entity set; that is, each entity instance of the supertype may appear in more than one subtype. a. True b. False 2. Within a specialisation hierarchy, every subtype can have many supertypes to which it is directly related. a. True b. False 3. If Capricon TVET College had some departments that were classified as “research only,” they would not offer courses; therefore, the COURSE entity would be independent to the DEPARTMENT entity. a. True b. False 4. A cloud database is a database that is built, deployed, and accessed in a cloud environment, such as a private, public, or hybrid cloud. a. True b. False 5. The multivalued type of attribute cannot be created in a DBMS. a. True b. False 3 INF2603 OCTOBER/NOVEMBER 2024 TURN OVER For question 6 to 10: Identify the choice that best completes the statement or answer the question. (2 marks each): a. CHECK b. HAVING c. EXISTS d. UPDATE e. LIKE 6. Validates data in an attribute. 7. Checks whether a subquery returns any rows. 8. Restricts the selection of grouped rows based on a condition. 9. Modifies an attribute’s values in one or more table’s rows. 10. Checks whether an attribute value matches a given string pattern QUESTION 2 [22 marks] a. What is the difference between a column constraint and a table constraint? (4) b. Explain what is a disjoint subtype? And give an example. (4) c. What three join types are included in the OUTER JOIN classification? (6) d. What is a strong (or identifying) relationship? (2) e. Why is a table whose primary key consists of a single attribute automatically in 2NF when it is in 1NF? (2) f. What is metadata? (2) g. Explain what is physical independence in data models? (2) QUESTION 3 [18 marks] University of Botswana Course Enrolment Database UniBo database stores information about students, courses, and enrolments. Initially, the data might be stored in a single table like this: Table 3.1: University Table StudentID StudentName CourseID CourseName Instructor EnrolmentDate 1 Thato 101 Math Dr. Moape 2 Lucas 102 History Dr. Mtsweni 1 Thato 103 Physics Dr. Chipa 3 Sam 101 Math Dr. Moape Given that information, answer the following questions: a. If possible, transfer the unnormalized form to first normal form. (4) 5 INF2603 OCTOBER/NOVEMBER 2024 TURN OVER b. Using the answer to problem a, remove existing partial dependencies and transform the relation into 2nd normal form. (6) c. Remove transitive dependencies and transform the relations from 2nd normal form to 3rd normal form. (8) QUESTION 4 [20 marks] Using the following transport business rules, draw the appropriate ERD using UML notation for a unique e-hailing taxi service in Mpumalanga. Make sure that you include all appropriate entities, relationships, and multiplicities: • One driver can be assigned to multiple taxis over time, but each taxi has only one driver at a time • Each customer can have multiple rides, and the e-hailing services offer sharing options for the customers • One taxi can be used for multiple rides • Each ride has one payment, and the customer can decide to cancel and the payment will be reversed