PRINCIPLES OF DATA MANAGEMENT BCS, THE CHARTERED INSTITUTE FOR IT BCS, The Chartered Institute for IT champions the global IT profession and the interests of individuals engaged in that profession for the benefit of all We promote wider social and economic progress through the advancement of information technology science and practice We bring together industry, academics, practitioners and government to share knowledge, promote new thinking, inform the design of new curricula, shape public policy and inform the public Our vision is to be a world-class organisation for IT Our 70,000 strong membership includes practitioners, businesses, academics and students in the UK and internationally We deliver a range of professional development tools for practitioners and employees A leading IT qualification body, we offer a range of widely recognised qualifications Further Information BCS, The Chartered Institute for IT, First Floor, Block D, North Star House, North Star Avenue, Swindon, SN2 1FA, United Kingdom T +44 (0) 1793 417 424 F +44 (0) 1793 417 444 www.bcs.org/contact PRINCIPLES OF DATA MANAGEMENT FACILITATING INFORMATION SHARING Second edition Keith Gordon © Keith Gordon 2013 The right of Keith Gordon to be identified as author of this work has been asserted by him in accordance with Sections 77 and 78 of the Copyright, Designs and Patents Act 1988 All rights reserved Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted by the Copyright Designs and Patents Act 1988, no part of this publication may be reproduced, stored or transmitted in any form or by any means, except with the prior permission in writing of the publisher, or in the case of reprographic reproduction, in accordance with the terms of the licences issued by the Copyright Licensing Agency Enquiries for permission to reproduce material outside those terms should be directed to the publisher All trade marks, registered names etc acknowledged in this publication are the property of their respective owners BCS and the BCS logo are the registered trade marks of the British Computer Society, charity number 292786 (BCS) Published by BCS Learning and Development Ltd, a wholly owned subsidiary of BCS, The Chartered Institute for IT, First Floor, Block D, North Star House, North Star Avenue, Swindon, SN2 1FA, UK www.bcs.org Paperback ISBN: 978-1-78017-184-5 PDF ISBN: 978-1-78017-185-2 ePUB ISBN: 978-1-78017-186-9 Kindle ISBN: 978-1-78017-187-6 British Cataloguing in Publication Data A CIP catalogue record for this book is available at the British Library Disclaimer: The views expressed in this book are of the author(s) and not necessarily reflect the views of the Institute or BCS Learning and Development Ltd except where explicitly stated as such Although every care has been taken by the authors and BCS Learning and Development Ltd in the preparation of the publication, no warranty is given by the authors or BCS Learning and Development Ltd as publisher as to the accuracy or completeness of the information contained within it and neither the authors nor BCS Learning and Development Ltd shall be responsible or liable for any loss or damage whatsoever arising by virtue of such information or any instructions or advice contained within this publication or by any of the aforementioned Typeset by Lapiz Digital Services, Chennai, India Printed at CPI Antony Rowe Ltd, Chippenham, UK iv There is nothing more difficult to take in hand, more perilous to conduct, or more uncertain in its success, than to take the lead in the introduction of a new order of things Niccolo Machiavelli (1469–1527) The beginning of wisdom is the definition of terms Socrates (470–399 BC) Data analysis is a very useful tool for efficient database design It is much less useful as a means of identifying information requirements (especially where these are ’fuzzy’ and unstructured), or in allowing different viewpoints to be taken into consideration Too often based on an analysis of current situations, data analysis – in the extreme case – is a great way of encapsulating organisational ineffectiveness in the resultant database! Professor Robert Galliers (1947–) v CONTENTS List of figures and tables xi Authorxiv Foreword to the first edition xv Glossaryxvii Prefacexxii Introductionxxv PART 1: PRELIMINARIES1 DATA AND THE ENTERPRISE3 Information is a key business resource The relationship between information and data The importance of the quality of data The common problems with data An enterprise-wide view of data Managing data is a business issue 10 Summary11 DATABASE DEVELOPMENT 12 The database architecture of an information system 12 An overview of the database development process 17 Conceptual data modelling (from a project-level perspective) 22 Relational data analysis 39 The roles of a data model 51 Physical database design 52 Summary55 WHAT IS DATA MANAGEMENT?  57 The problems encountered without data management 57 Data management responsibilities 59 Data management activities 60 Roles within data management 63 The benefits of data management 64 The relationship between data management and enterprise 65 architecture Summary66 vii Principles of Data Management PART 2: DATA ADMINISTRATION67 CORPORATE DATA MODELLING 69 Why develop a corporate data model? 69 The nature of a corporate data model 70 How to develop a corporate data model 72 Corporate data model principles 74 Summary78 DATA DEFINITION AND NAMING 80 The elements of a data definition 80 Data naming conventions 84 Summary86 METADATA87 What is metadata? 87 Metadata for data management 87 Metadata for content management 88 Metadata for describing data values 89 Summary90 DATA QUALITY 91 What is data quality? 91 Issues associated with poor data quality 91 The causes of poor data quality 92 The dimensions of data quality 93 Data model quality 94 Improving data quality 95 Summary98 DATA ACCESSIBILITY 99 Data security 99 Data integrity 104 Data recovery 106 Summary108 MASTER DATA MANAGEMENT  109 What is master data? 109 How problems with master data occur? 112 How we manage master data? 112 Summary114 PART 3: DATABASE AND REPOSITORY ADMINISTRATION115 10 viii DATABASE ADMINISTRATION 117 Database administration responsibilities 117 Performance monitoring and tuning 119 Summary120 ... collection of data files under the control of a database management system Database administration  A role in data management concerned with the management and control of the software used to access... within data management 63 The benefits of data management 64 The relationship between data management and enterprise 65 architecture Summary66 vii Principles of Data Management PART 2: DATA. .. Restricted terms used in the naming of entity types Restricted terms used in the naming of domains Restricted terms used in the naming of attributes Restricted terms used in the naming of relationships