The main aim of this work is to provide one readable text of essential core material for further education, higher education and commercial courses on database systems. The current volume is designed to form a consolidated, introductory text on modern database technology and the development of database systems.

It is undoubtedly true that database systems hold a prominent place in most contemporary approaches to the development of information systems. It is this practical emphasis on the use of database systems for information systems work that distinguishes the current volume from other texts on the subject. This work therefore forms a companion volume to Information Systems Development: an introduction to information systems engineering, also published by Macmillan

The text is built from the author’s experiences of running a number of academic and commercial courses on database technology and database development for several years.

The second edition has been much expanded from approximately 300 to some 500 pages. This expansion has enabled us to cover particular topics in more depth:

1. Greater coverage has been devoted to the kernel functions of contemporary DBMS: file organisation, access mechanisms, transaction management etc.
2. Material has been added on contemporary database applications such as data warehousing, data mining and on-line analytical processing
3. A chapter on Microsoft Access has been included
4. Material has been provided on extended-relational and object-oriented data management standards
5. The topic of strategic data planning has been addressed
6. More detail is provided on the issue of physical database design and database implementation

We have also updated many chapters with developments since 1996 and re-organised a number of chapters to provide a more coherent presentation of key topics.

The text is organised into a number of parts:

1. Fundamentals. The introductory chapters set the scene for the core of the text. We begin with a description of the key features of a database system. We then move on to define some key concepts and illustrate the importance of database technology to contemporary information systems. We close this part with an example of some of the key features of the data management layer of an information technology system.
2. Data Models. Part two explores a number of contemporary architectures for database systems. Because of its current dominance, particular emphasis is made of the relational data model, although developments in object-oriented data management explain the extended coverage offered. We also consider two historically important data models - hierarchical and network - and another data model significant because of its association with ‘intelligent’ applications - the deductive data model. We close this part with a consideration of a hybrid data model - the extended or post-relational data model - which is important because of its popularity amongst contemporary DBMS.
3. DBMS Interface and Toolkit. Part three addresses the issue of the standard interface to DBMS - SQL. We also consider the toolkit of products that can be used in association with DBMS. The toolkit is divided into end-user tools, database administration tools and application development tools.
4. DBMS Kernel. Part four considers some of the critical functions of the kernel of a database management system (DBMS): file organisation, access mechanisms, transaction management.
5. Systems and Standards. Part five discusses the architectures and facilities available in three contemporary DBMS, two relational (Microsoft Access and Oracle) and one object-oriented (O₂). We also consider developments amongst the SQL3 and ODMG standards for DBMS.
6. Development. Part six represents a discussion of the major techniques utilised in the design and implementation of database systems. We discuss the techniques of entity-relationship diagramming, normalisation and object modelling, each of which is particularly useful in the early stages of database design. We conclude with a review of a number of issues involved in the physical design of databases and database implementation.
7. Planning and Administration. The issue of planning and administering data in organisations is considered in this part. We first consider the issue of using corporate data models to plan for database systems. This is followed by a consideration of the importance of administering data within organisations. We conclude with a review of the database administration function.
8. Trends. Part eight considers new applications for databases. It consists of three chapters which look at areas having a significant effect on the functionality of database systems: the issue of parallelism, the issue of distribution and the issue of handling complex data.
9. Applications. This part discusses four contemporary applications for database systems: data warehousing, OLAP, data mining, networked databases.

The author is keen to receive feedback on the current text. Any comments or suggestions should be addressed to the author (pbeynon@glamorgan.ac.uk). A teaching pack is available from the author. My thanks to staff and students at the university of Glamorgan and to professor Frank Sumner for writing chapter 32.

Below we indicate some ways in which the material may be used in educational modules and courses. This is meant to be purely suggestive.

An introductory module in database systems should provide a basic understanding of database concepts and an appreciation of database development issues. For this purpose the following chapters are suggestive: 3 chapters in fundamentals; relational data model; SQL; Access; Normalisation; E-R diagramming.

An intermediate module should impart an understanding of the architecture of a DBMS and issues pertaining to physical design and database administration. For this purpose the following chapters are suggestive: kernel chapters; toolkit chapters; Oracle; database administration; physical design; database implementation.

Advanced modules in database systems should provide an awareness of alternative approaches to handling data and developing database systems over and above that provided by the relational data model and relational databases. For this purpose the following chapters are suggestive: classic data models, OO data model, deductive data model, post-relational data model; O2; object modelling; strategic data planning; data administration; trends.

Access^TM and SQL Server^TM are trademarks of Microsoft

O₂^TM is a trademark of O₂ Technology

ORACLE^TM is a trademark of the Oracle corporation