Foreword

Three years ago, at the dawn of the Internet revolution, I wrote the foreword to the first edition of this book. Today, the infrastructure that we saw emerging is solidly in place and is being used in ways we could not have predicted just 36 short months ago.

Intelligent management of information is essential to the challenges we face in business and in ensuring our safety and security in daily life. Data warehouses are uniquely able to bring together information to identify trends, and understand how to maximize effective use of resources.

The ability to capture accurate, usable, and timely information, integrate it with other data, analyze it, and deliver it via the web to employees, customers, suppliers, and partners has become key to running a successful enterprise. Heretofore, data warehouses were used to aid in the strategic decision making process of a business. Today, they are also being used for tactical decision making, and to support day-to-day operations. While data warehouses were once considered "nice to have," twenty-first century organizations cannot run effectively without them.

Data warehouse growth, both in usage, and size, is accelerating rapidly.

Today, Oracle data warehouses frequently contain over a terabyte of data. Within the next five years some organizations will find themselves managing petabytes of data. The Internet has enabled instant, on demand accessibility of information, to a much larger set of user populations. Some Oracle data warehouses in operation today already have thousands of online users.

The days of waiting overnight for a report to run are long gone, along with the concordant slow decision-making. By using Oracle 9i, pre-summarizing data and storing it in materialized views, reports that used to take 2 hours to run, now complete in 2 minutes. Some Oracle sites run over 150,000 reports and queries in a single day. With new analytic capabilities in the Oracle 9i database, OLAP queries can execute directly on data stored in the Oracle data warehouse.

Oracle 9i warehouses are now loaded daily, and even multiple times a day using transportable tablespaces, SQL*Loader, external tables, and partition maintenance operations, rather than updating the warehouse periodically in batch, on weekends.

Data warehouses have become the source of data for critical applications including customer relationship management (CRM) and supply chain management (SCM). They are increasingly being used for fraud detection as well. Data Mining capabilities, which have been incorporated into the Oracle database can be used to help detect if the activity of an account increases suddenly or usage patterns change.

Whether you are designing a large data warehouse, small data marts, or looking for tips on how to improve performance using Oracle 9i Release 2, this book will provide you with advice and examples you can follow.

Recommended techniques are illustrated with numerous working examples in each chapter. Written by Lilian Hobbs, Susan Hillson, and Shilpa Lawande, members of the Oracle Server Technologies development team, this book offers a thorough coverage of the data warehousing features in Oracle 9i Release 2, the tools in Oracle 9i Application Server and Oracle 9i Developer Suite used to build, access, and manage your data warehouse.

Chuck Rozwat
Execute Vice President
Server Technologies
Oracle Corporation