Introduction

Welcome to Dimensional Data Warehousing with MySQL: A Tutorial.

Data warehousing enables unified information delivery by collecting data from various operational and administrative information systems already in operation and possibly from external data sources. The data from these sources are integrated, cleaned and transformed, and stored for easier access than if the data has to be read directly from the sources.

The data structure in a data warehouse allows you to store current and historical data. Current information is needed for operational activities, mostly for producing regular hardcopy or online reports. Historical data, unlikely to be readily available from the source, provides the business with information for time-based analysis such as tracking, trend analysis, and comparison, all of which are important for long-term planning and strategic decision-making.

Integrating data from multiple sources, storing and accumulating the data regularly, and providing fast access to it require design and development techniques that are different from techniques used in operational and administrative systems. This book is all about data warehousing design and development techniques. It covers most commonly used techniques in the phases of building a data warehouse. More important, this book provides an easy to follow tutorial for developing a real world data warehouse.