Part I. Introduction

For managing an organization, especially for managing a business enterprise, large amounts of information (about people, projects, products, interactions with customers, etc.) have to be collected, stored, updated, retrieved, evaluated and used in many different ways. Today, all this information is managed and used with the help of information and communication technologies, most notably with database technologies.

There are different paradigms for databases. For many years, the most important database paradigm for implementing business information systems are relational databases, which have been proposed by E.F. Codd in 1970.

An organization acts in a particular domain. For instance, a university acts in the domain of tertiary education, while a bank acts in the financial domain.

Since the real world essentially consists of objects and events, which may be collectively called entities, and their relationships with each other, a database managed by an organization has to be able to represent information about entities and about their relationships with each other. Entity Relationship Diagrams, discussed in II. Information Modeling, are a classical visual modeling language for capturing the business vocabulary of a domain as a basis for database design.

In a relational database, there are entity tables representing entity types, and relationship tables representing relationship types, such that the rows of a table represent entities or relationships.