I created this almost exactly five years ago for a presentation where I was trying to explain why a MySQL database might be overkill.
I still think it’s quite helpful since several times a year I encounter someone who is using the wrong approach to manage their data. The situation that really puzzles me are the people who fret about what kind of SQL database engine they need to store files. I’ve lost track of the number of times I’ve said something like, "Why not put your files in a database designed especially for files? It’s called a file system."