Where do we start? One of the problems in comprehending a massive product such as the Oracle database is the difficulty of getting a good sense of how the product works without getting lost in the details of implementing specific solutions. This book aims to solve this problem by giving you a thorough grounding in the concepts and technologies that form the foundation of the Oracle Database Server. Oracle also provides an Application Server and business applications, including the E-Business Suite and the Oracle Collaboration Suite,[1] which are outside the scope of the main body of this book.
[1] Previous versions of this book did cover iFS. In Oracle Database 10g, however, this product is now known as Oracle Files and is now a part of the Oracle Collaboration Suite. For this reason, iFS is not covered in this edition.
We've tried to write a book for a wide range of Oracle users, from the novice to the experienced user. To address this range of users, we've focused on the concepts and technology behind the Oracle database. Once you fully understand these facets of the product, you'll be able to handle the particulars of virtually any type of Oracle database. Without this understanding, you may feel overburdened as you try to connect the dots of Oracle's voluminous feature set and documentation.
This first chapter lays the groundwork for the rest of the discussions in this book. Of all the chapters, it covers the broadest range of topics; most of these are discussed further later in the book, but some of the basicsfor example, the brief history of Oracle and the contents of the different "flavors" of the Oracle database productsare unique to this chapter.
Oracle has grown from its humble beginnings as one of a number of databases available in the 1970s to the market leader of today. In its early days, Oracle Corporation was known more as an aggressive sales and promotion organization than a technology supplier. Over the years, the Oracle database has grown in depth and quality, and its technical capabilities now are generally recognized as the most advanced. With each release, Oracle has added more power and features to its already solid base while improving the manageability.
Several recent Oracle database releases are the focus of this book:
Oracle8i, released in 1999, added a new twist to the Oracle databasea combination of enhancements that made the Oracle8i database the focal point of the world of Internet (the i in 8i) computing.
Oracle9i, released in 2001, introduced Real Application Clusters as a replacement for Oracle Parallel Server, and added many management and data warehousing features.
Oracle Database 10g
Oracle Database 10g, released in 2003 and the current release, enables grid (the g in 10g) computing. A grid is simply a pool of computers that provides needed resources for applications on an as-needed basis. The goal is to provide computing resources that transparently scale to the user community, much as an electrical utility company can deliver power to meet peak demand by accessing energy from other power providers' plants via a power grid. Oracle Database 10g further reduces the time, cost, and complexity of database management through the introduction of self-managing features such as the Automated Database Diagnostic Monitor, Automated Shared Memory Tuning, Automated Storage Management, and Automated Disk Based Backup and Recovery. One important key to Oracle Database 10g's usefulness in grid computing is the ability to provision CPUs and data.
Before we dive into the specific foundations of these releases, we must spend a little time describing some Oracle basicshow databases evolved to arrive at the relational model, a brief history of Oracle Corporation, and an introduction to the basic features and configurations of the database.