Chapter List

Overview

This chapter begins Part I of this book, focusing on data warehouse data model tuning techniques. This first chapter describes how to build data warehouse data models and how to relate data warehouse entities to each other. There are various methodologies and approaches, which are essentially very simple. Tuning data warehouse entities is directly related to four things: (1) time how far back does your data go, (2) granularity how much detail should you keep, (3) denormalizing including duplication in entity structures, (4) using special Oracle Database logical structures and techniques, such as materialized views.

• This chapter uses a schema designed for tracking the shipping of containers by sea, on large container vessels.

• The word entity in a data model is synonymous with the word table in a database.

1.1 The Relational and Object Data Models

Before attempting to explain data warehouse data modeling techniques, it is necessary to understand other modeling techniques, and why they do not cater for data warehouse requirements. In other words, it is best to understand the basics of relational data modeling, and perhaps even some object data modeling, in order to fully understand the simplicity of data warehouse data modeling solutions.