Okay, so I'm well aware of what the "overhead" in PHPMyAdmin actually MEANS, but I have no idea how to actually get that value. I'm pretty sure it has something to do with taking the actual file data size from show table status, and somehow calculating what the file size SHOULD be, but kind of getting lost there. I'm basically trying to create basically a self-fixer for my clients, so they can log in and it'll show them when something is wrong, and instead of having to call me to login and click "repair", they could do it themselves. I'd prefer not to just have an "Optimize all" as the only form of optimizing the tables, anyone have some ideas?