Database Concepts - Data Warehouse Systems: Design and Implementation - page 11

Chapter 2
Database Concepts
This chapter introduces the basic database concepts, covering modeling,
design, and implementation aspects. Section 2.1 begins by describing the
concepts underlying database systems and the typical four-step process used
for designing them, starting with requirements specification, followed by
conceptual, logical, and physical design. These steps allow a separation of
concerns, where requirements specification gathers the requirements about
the application and its environment, conceptual design targets the modeling
of these requirements from the perspective of the users, logical design develops
an implementation of the application according to a particular database
technology, and physical design optimizes the application with respect to a
particular implementation platform. Section 2.2 presents the Northwind case
study that we will use throughout the topic. In Sect. 2.3 , we review the entity-
relationship model, a popular conceptual model for designing databases.
Section 2.4 is devoted to the most used logical model of databases, the
relational model. Finally, physical design considerations for databases are
covered in Sect. 2.5 .
The aim of this chapter is to provide the necessary knowledge to
understand the remaining chapters in this topic, making it self-contained.
However, we do not intend to be comprehensive and refer the interested
reader to the many textbooks on the subject.
2.1 Database Design
Databases constitute the core component of today's information systems. A
database is a shared collection of logically related data, and a description of
that data, designed to meet the information needs and support the activities
of an organization. A database is deployed on a database management
system (DBMS), which is a software system used to define, create, manip-
ulate, and administer a database.