This book is about POSTGRESQL, the most advanced open source database. From its origins in academia, POSTGRESQL has moved to the Internet with explosive growth. It is hard to believe the advances during the past four years under the guidance of a team of worldwide Internet developers. This book is a testament to their vision, and to the success that POSTGRESQL has become.

The book is designed to lead the reader from their first database query through the complex queries needed to solve real-world problems. No knowledge of database theory or practice is required. However, basic knowledge of operating system capabilities is expected, such as the ability to type at an operating system prompt.

Beginning with a short history of POSTGRESQL, the book moves from simple queries to the most important database commands. Common problems are covered early, which should prevent users from getting stuck with queries that fail. The author has seen many bug reports in the past few years and consequently has attempted to warn readers about the common pitfalls.

With a firm foundation established, additional commands are introduced. The later chapters outline complex topics like transactions and performance.

At each step, the purpose of each command is clearly illustrated. The goal is to have readers understand more than query syntax. They should know why each command is valuable, so they can use the proper commands in their real-world database applications.

A database novice should read the entire book, while skimming over the later chapters. The complex nature of database systems should not prevent readers from getting started. Test databases offer a safe way to try queries. As readers gain experience, later chapters will begin to make more sense. Experienced database users can skip the early chapters on basic SQL functionality. The cross-referencing of sections allows you to quickly move from general to more specific information.

Much information has been moved out of the main body of the book into appendices. Appendix A lists sources of additional information about POSTGRESQL.Appendix B provides information about installing POSTGRESQL. Appendix C lists the features of POSTGRESQL not found in other database systems. Appendix D contains a copy of the POSTGRESQL manual pages which should be consulted anytime you have trouble with query syntax. Also, do not overlook the excellent documentation that is part of POSTGRESQL. This documentation covers many complex topics, including much POSTGRESQL-specific functionality that cannot be covered in a book of this length. Sections of the documentation are referenced in this book where appropriate.

This book uses italics for identifiers, SMALLCAPS for SQL keywords, and a monospaced font for SQL queries. The Web site for this book is located at postgresql/docs/awbook.html. 0201703319P04062001