Computer science · 2015 · November · Paper 2 · HL · Question paper

N15/4/COMSC/HP2/ENG/TZ0/XX Computer science Higher level Paper 2 © International Baccalaureate Organization 2015 20 pages 8815 – 7012 Wednesday 18 November 2015 (morning) Instructions to candidates • Do not open this examination paper until instructed to do so. • Answer all of the questions from one of the options. • The maximum mark for this examination paper is [65 marks]. Option Questions Option A – Databases 1–4 Option B – Modelling and simulation 5–8 Option C – Web science 9–13 Option D – Object-oriented programming 14–19 1 hour 20 minutes – 2 – Option A — Databases 1. After attending a database course, Paul, the owner of a small shop, decided to create and implement a customer database. (a) (i) Identify one benefit of creating a database. [1] (ii) Identify one cost of the implementation. [1] Consider this section of his customer database file. CustomerTable Name Date ItemOrdered QuantityOrdered InvoiceAmount Ann Low 18/04/2015 1713 4 200.00 Boris Nicke 18/04/2015 1324 3 180.00 Greta Pink 18/04/2015 1713 3 150.00 Rob Nool 19/04/2015 1648 7 360.00 Ann Low 19/04/2015 1713 5 250.00 Ivor Turk 20/04/2015 1423 6 105.00 (b) (i) State the number of fields that are in each record of the CustomerTable. [1] (ii) Describe, using an example from the table above, why the customer’s name is not an appropriate primary key. [2] (iii) Define the term secondary key. [1] (c) Describe the steps in a query that will list all items for which more than five were ordered on 19/04/2015. [4] Paul finds that the response time that will database queries is very slow. (d) Explain what Paul could do to improve the response time without making changes to his hardware. [5] (Option A continues on the following page) N15/4/COMSC/HP2/ENG/TZ0/XX