6 (1500U40-1) © WJEC CBAC Ltd. 10. (a) Describe what is meant by the term relational database. [2] (b) Describe the advantages of database normalisation. [4] A health care company is creating a relational database to manage its dental surgeries located in different towns across Wales. Each dental surgery employs dentists who will only work in that surgery. Patients will be registered with one of the dentists and will only be treated by that dentist. Patients will book appointments to see their dentist. (c) Produce an entity relationship diagram for the system described. [3] (d) Design a database structure in third normal form for the system. [3] 11. The increase in speed due to parallel processing can be calculated as: where P = parallel fraction, N = number of processors and S = serial fraction. (S = 1 – P) (a) Calculate the increase in speed due to parallel processing using 10 processors and the increase in speed of doing the same task using 1000 processors, where the parallel fraction P is equal to: • 0.5 for 10 and 1000 processors • 0.9 for 10 and 1000 processors [4] (b) Discuss the effect that increasing the parallel fraction of the task will have on the speed due to parallel processing. [3] 12. Describe the advantages of using a distributed database. [4] 13. Cryptography may be based on symmetric or asymmetric algorithms. Describe the advantages of using asymmetric encryption. [6] 14. A local hospital needs to ensure that access to its medical laboratories is restricted to authorised personnel. It is considering using biometric technologies to identify and restrict access to authorised personnel only. Describe the biometric options available to the hospital and explain the main benefits and drawbacks of biometric security technologies. [9] END OF PAPER 1 P s + N S BLANK PAGE (1500U40-1) 7 © WJEC CBAC Ltd.