prototype-based image preloader

Preloading images is often a final optimization step when writing a javascript heavy web app. I think its generally because its seen as a pita, so it keep getting pushed as the site is developed until you get to the very end, and something has to be re-engineered to make it look right. [...]


counter_cache as an optimization step

I had a debate with a programmer friend of mine once about optimization. I argued that once you get past adding indexes to a relational database, every attempt at increasing its speed or scaling is an act of denormalization. Whether its double storing information in the database in such a way that it [...]