Book excerpt: Ready to go to the next level with Rails? From examining the parts of Ruby that make this framework possible to deploying large Rails applications, Advanced Rails offers you an in-depth look at techniques for dealing with databases, security, performance, web services and much more. Chapters in this book help you understand not only the tricks and techniques used within the Rails framework itself, but also how to make use of ideas borrowed from other programming paradigms. Advanced Rails pays particular attention to building applications that scale -- whether "scale" means handling more users, or working with a bigger and more complex database. You'll find plenty of examples and code samples that explain: Aspects of Ruby that are often confusing or misunderstood Metaprogramming How to develop Rails plug-ins Different database management systems Advanced database features, including triggers, rules, and stored procedures How to connect to multiple databases When to use the Active Support library for generic, reusable functions Security principles for web application design, and security issues endemic to the Web When and when not to optimize performance Why version control and issue tracking systems are essential to any large or long-lived Rails project Advanced Rails also gives you a look at REST for developing web services, ways to incorporate and extend Rails, how to use internationalization, and many other topics. If you're just starting out with rails, or merely experimenting with the framework, this book is not for you. But if you want to improve your skills with Rails through advanced techniques, this book is essential.