When the subject of optimizations is discussed, regardless of language, the single most important thing that must be done is to determine where the bottlenecks are in your application. After all, if you do not know what exactly is slowing your applications down (called profiling), there is no way to fix the problem.
Although many professional-quality tools exist to assist you in profiling your applications, the techniques employed in optimization often don't require them. For all but the most heavily-used applications, profiling can be accomplished using nothing more than a simple PHP script. For your convenience, I have written such a script that is designed to be used as a template for your basic profiling needs (see ). This script will be used to profile all the optimization techniques I will be discussing in this chapter.
