No doubt you occasionally need to push logic down to the database, much in the same way that you sometimes need to uglify your code to make it fast enough, but

No doubt you occasionally need to push logic down to the database, much in the same way that you sometimes need to uglify your code to make it fast enough, but in my experience, it's a good way to get a painful-to-manage codebase full of fantastic ideas such as "let's build this complex XML structure by concatenating strings".