I recommend this book highly to every developer I work with, and to every class that I teach. This is the definitive reference for PL/SQL, a dog-eared, constantly used reference for beginners and advanced programmers alike. Several other books try to cover the PL/SQL language, but none have the detail level, comprehensive discussions, and examples of this book.

Normally, I do not buy "2nd" edition releases, since they add little to the original -- this book is an improvement on the first. With the other PL/SQL books from O'Reilly (Programmning with Packages and Oracle Built-ins) this is a complete reference shelf for Oracle developers.