If there's something we developers are really bad at, it's guessing. We think we know which parts of our application are slow, and spend a lot of time optimising those, but in reality the bottlenecks are often somewhere else. The only sane thing to do is measuring, with the help of some profiling tools.

PHP Code Sniffer (PHPCS) is a package for syntax checking, available from PEAR. It can check code against defined rules covering anything from whitespace through doc comments to variable naming conventions and beyond. In this article we'll look at getting started with PHPCS, using it to syntax check our files, and go further to look at how the rules are create and the standards defined.

Graphs are ubiquitous. Social or P2P networks, thesauri, route planning systems, recommendation systems, collaborative filtering, even the World Wide Web itself is ultimately a graph! Given their importance, it's surely worth spending some time in studying some algorithms and models to represent and work with them effectively. In this short article, we're going to see how we can store a graph in a DBMS.