Database Development (H4)

Transcription

1 IMIS HIGHER DIPLOMA QUALIFICATIONS Database Development (H4) Thursday 30 th November :00hrs 13:00hrs DURATION: 3 HOURS Candidates should answer ALL EIGHT questions in Part A and THREE of the FIVE questions in Part B. Part A carries 40% of the marks available and Part B carries 60%. Candidates should allocate their time accordingly. No reference material of any kind may be taken into the examination. [Turn over] Page 1 of 5

2 Question A1 PART A: Answer ALL EIGHT questions in this section Describe what is meant by logical data independence and provide an example. Question A2 Describe the key components of a conceptual model that you are familiar with. Include a brief diagram to illustrate the model chosen. Question A3 Structured Query Language (SQL) commands can be categorised as Data Manipulation Language (DML) or Data Definition Language (DDL) commands. Using examples, explain the difference between DML and DDL commands. Question A4 Indexes are an important technique to aid Structured Query Language (SQL) performance. Describe two situations where an index should be used. Question A5 Describe the main advantages of using a distributed database management system. Question A6 Briefly explain the Extraction step of the Extraction, Transformation and Loading (ETL) process of a data warehouse. Question A7 In the database systems development lifecycle describe what steps can be taken to determine the user requirements. Question A8 Describe two problems that can occur with developing and managing a data warehouse. Page 2 of 5

3 Part B: Answer ANY THREE of the following FIVE questions Question B9 A University is developing a new Student Information System. Describe the role of the following personnel in developing the system: a) Data administrator b) Database Designer c) Application Developers d) End-users Question B10 a) Describe the key features of the following data models: i. Hierarchical and network model ii. Relational model iii. Object oriented model (15 marks) b) Describe, with examples, two advantages of ONE of the above data models. Page 3 of 5

4 Question B11 Given the following tables that represent part of a sales order system: Order Column name Data type Constraints/Comments OrderNo NUMBER(8) Primary key OrderDate DATE Date the order was made DeliveryDate DATE Date the order is delivered, it must be the same or later than the OrderDate CourierRef VARCHAR(20) A unique reference number provided by the courier for the delivery. TotalCost NUMBER(7,2) Total cost of the order. A business rule that states an order cannot be for less than 50. Order_Line (an order can be for many items) Column name Data type Constraints/Comments OrderNo NUMBER(8) Part of a composite primary key; A foreign key to Order ItemNo NUMBER(5) Part of a composite primary key Quantity NUMBER(3) The number of items ordered. This is a number between 1 and 100 a) Write SQL code to create the ORDER table, including all constraints identified. (10 marks) b) Write SQL code to create the ORDER_LINE table, including all constraints identified. (8 marks) c) Most database management systems will create an index automatically on the primary key field. Pick ONE other field that could benefit from an index, explaining why. (2 marks) Page 4 of 5

5 Question B12 There are different approaches to fragmentation in a distributed database. Using suitable examples to illustrate your answer: a) Explain why fragmentation is needed b) Describe two main types of fragmentation c) Discuss what problems can occur from fragmentation (10 marks) Question B13 Describe the following data mining operations and give an example of an application where they can be used: a) Predictive modelling b) Database segmentation c) Link analysis d) Deviation Detection END OF EXAMINATION Page 5 of 5