In this guide I will explain best practise regarding performance in MySQL, PHP and of course our loved Yii Framework. Since this is a complex topic, I will start with some basics and then expand this guide from time to time. Since this wiki can become big, you may click on View history - there you can see what changes have been made, so you don't miss anything.
One of the common tasks the web application might be required to perform, especially the app using some kind of a CMS, is to save the history of data changes. Your client for sure will want the answer to this simple question - If I mess this up or delete by accident can we bring it back? Well, DB backup is one thing and quick recovery is another - let's talk about latter one.