Principles of Database Management The Practical Guide to Storing, Managing and Analyzing Big and Small Data

Chapter Objectives

In this chapter, you will learn to:

This chapter deals with physical database organization in its broadest sense. A primary focus is on physical database design – the translation of a logical data model into an internal data model, including the design of indexes to speed up data access. In this respect, this chapter builds on the insights gained from Chapter 12 in relation to physical record and file organization. However, we also zoom out to other concerns of physical data storage, such as technological and management aspects, as well as the important area of business continuity.

First, we discuss the concepts of tablespaces and index spaces, as well as other basic building blocks of physical database organization. The principles of file organization acquired in the previous chapter are then applied in the context of database organization. Here, we deal with the role of the query optimizer and how the latter uses indexes and other techniques to determine the optimal access plan to execute a query. We also pay particular attention to different alternatives for join implementation. In the second half of this chapter, we return to storage hardware, but now from a more global perspective than in Chapter 12. We deal with RAID technology and different approaches to networked storage, such as SAN and NAS. We conclude with a discussion on how these techniques can be applied in the context of business continuity. By no means do we claim exhaustiveness with respect to the topics covered in this chapter. Rather, we aim to provide the reader with a broad perspective on the many angles and concerns of physical data storage and management.