Question 2a: [Marks =10] A football club uses the table below to record details of players and the positions in which they can play. Each player can play in up to a maximum of three positions: playerID | playerName | Positions ---|---|--- P1 | Lionel Messi | Forward, Centre Midfield P2 | Cristiano Ronaldo | Forward, Left Midfield, Right Midfield P3 | Philippa Lahm | Right Back, Defensive Midfield (i) Explain why this table is not in "First Normal Form" (1NF). (2 marks) (ii) Show how this table can be transformed into 1NF tables. Give two possible solutions. (8 marks) Question 2b: [Marks =10] The table shown below stores details of students and the overall grade each student obtained in different modules. The Primary Key is (StudentID, ModuleID). StudentID | StudentName | ModuleID | ModuleName | Grade ---|---|---|---|--- S001 | Smith | M01 | Java | A S001 | Smith | M02 | Databases | B S002 | Ford | M01 | Java | B (i) Which Normal Form does the above table violate and why? (2 marks) (ii) Give an example of an update anomaly and an example of a delete anomaly that may occur if the table is left un-normalized. Explain the problems that a marks) (iii) Show how you would normalize the table. (4 marks)
Added by Jeffrey A.
Close
Step 1
Question 2a: (i) The table is not in Show more…
Show all steps
Your feedback will help us improve your experience
Akash M and 81 other AP CS educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Suppose that a railway company has a computer system for reserving seats on its trains, which stores data in a relational database. The seat reservation system must ensure that a seat on a train journey is not reserved by more than one passenger. Explain why concurrent access to the database is relatively easy during periods when all users are only checking whether seats are available. (2 marks) Describe a protocol that the company could use to ensure that schedules are conflict serializable. (3 marks) The locking information for five transactions of the seat reservation system is shown in Table 4. Produce a wait-for-graph for the transactions. (7 marks) Does deadlock occur? Justify your answer. (1 mark) Table 5 shows the company's transaction log file. Suppose that part of the seat reservation system fails at 20:06. Assume that the DBMS is using the Immediate Update protocol. Describe the actions that the recovery manager would take to recover from the failure. Explain why each action is taken. (8 marks) Describe how the recovery manager would use the recovery log during the recovery from the failure. State the order in which it would do things.
Akash M.
The table shown below displays the details of the roles played by actors/actresses in films. filmNo fTitle dirNo director actorNo aName role timeOnScreen FTOO Happy Days DIOI Jim Alan A1020 Sheila Toner Jean Sinson 15.445 DIOI Jim Alan Al222 Peter Watt Tom Kinder 25.38 DIOI Jim Alan A1020 Sheila Toner Silvia Simpson 22.56 FT109 Snake Bite D076 Sue Ramsay 1567 Steven McDonald Tim Rosey 19.56 D076 Suc Ramsay A[222 Peter Watt Archic Bold 0.44 a) Analyze why the table shown above is not in first normal form (1NF) b) The table shown above is susceptible to update anomalies. Provide examples of how insertion, deletion, and modification anomalies could occur on this table. c) Convert it into 1NF, 2NF, and 3NF.
Supreeta N.
Two groups of students (males and females) were examined in Statistics for Decision Making course. The following were the scores obtained by the males and females samples consisting of ten students each: Group A (Males): 60, 44, 43, 77, 80, 98, 68, 67, 60, 48 Group B (Females): 12, 55, 80, 68, 75, 50, 32, 90, 56, 42 i. For each group, calculate the mean score and interpret your result. (3 marks) ii. Which group had varied scores? (4 marks) Traditionally, the demand for Kakabo Local Rice is determined by a number of factors. An economist has collected data on few of these factors and has estimated their contribution to the purchase behavior of customers. The tables below indicate the regression output of the quantity of 5kg bag of Kakabo Local Rice. Use the information in the tables to answer the questions that follow: Regression Statistics Multiple R: 0.9965 R Square Adjusted R Square Standard Error: 0.5332 Observations: 21 ANOVA Df SS MS F Significance F Regression 4 653.761 163.440 574.928 0.000 Residual 16 4.548 0.284 Total 20 658.310 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept 9.104 7.352 1.238 0.233 -6.481 24.689 Price 0.137 -2.239 0.040 -0.599 -0.016 Income 0.267 0.127 0.051 -0.001 0.535 Taste 0.636 2.357 0.032 0.064 1.208 Population -0.050 -0.223 -0.527 0.427 i. State and explain the estimated equation for the 5kg bag of rice. (4 marks) ii. What percentage of the variation is not explained by the exogenous (independent) variables? (1 mark) iii. Which of the independent variable(s) is/are significant in explaining the changes in quantity of rice and why? (2 marks) iv. If price changes by 1 unit, state the range of values within which quantity will fall for 95% confidence level. (1 mark)
Sri K.
Recommended Textbooks
Computer Science and Information Technology
Introduction to Programming Using Python
Computer Science - An Overview
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD