CodeNotes for Oracle 9i

Chapter 1

INTRODUCTION

Modern Databases

The database is an integral component of almost every large computer system. Whether you are building a consumer e-commerce website or developing more traditional client-server systems for in-house use, the database provides the critical central storage area for your data. By now, most developers will be familiar with the power of a relational database. Simply browsing the web almost always involves interacting with one or more highly tuned databases. However, a database is much more than simply a storage container for data.

Modern databases, such as Oracle 9i, provide many features that make the database a powerful development tool. Many of the tasks that used to be exclusively performed by middle-tier systems, such as data translation (e.g., database to XML, or vice versa), can now be executed directly in the database. Actions that used to be confined inside the databases (stored procedures) can now be extended to outside systems (e.g., Java extended stored procedures). Oracle 9i, for instance, can now call Java code external to the database from inside a stored procedure.

Many of these enhancements to the modern database take advantage of the optimized data storage systems and can provide tremendous performance advantages over traditional three-tier systems development. Additionally, many of these common tasks are now built-in features, accessible through simple Application Programming Interfaces (APIs).

Ultimately, this book explains how to exploit these modern database enhancements. It?s a hands-on, practical guide, written for all ranges of Oracle developers. Most important, this book will make you productive with Oracle 9i in as short a time as possible. As you read this book, our hope is that you will come to appreciate the tools associated with Oracle 9i, as well as learn to build powerful and flexible database applications.

Oracle Products

The Oracle 9i database is actually one component within a suite of products, although it is definitely the heart of the product line. At the time of this writing, additional top-level Oracle products include:

* Oracle 9i Application Server (Oracle 9i AS)--Oracle 9i AS delivers J2EE performance with the reliability and security needed for professional business applications and websites.

* Oracle E-Business Suite 11i--A complete set of business applications designed to run entirely on the Internet. Oracle E-Business Suite 11i allows companies to cut costs across customer relationship management, supply chain, financial, project, human resources, and business intelligence functions.

* Oracle 9i JDeveloper--Oracle 9i JDeveloper is a J2EE/XML development environment designed to debug and deploy e-business applications and web services, quickly and easily.

As you will see throughout this book, each of these top-level products actually contains a wide variety of subcomponents. Throughout this book, we have tried to limit the use of the word Oracle to refer to either the Oracle Corporation or the Oracle database. All other Oracle products are referred to by their proper names.