A couple of users of our very popular MySQL Configuration Wizard have submitted feedback such as “I’d love to input my existing server settings and get suggestions on how to improve it.”
This sounds like it would be great, doesn’t it? We’ve considered doing this, and even partially implemented it. But during our pre-release testing, we found a lot of potentially serious problems with the idea. It turns out to be very subtle — perhaps too subtle to be done with any computer program, no matter how smart, because there might be a lot of assumptions it’s forced to make, which could turn out to be dangerous. Every approach we considered carried a high risk of de-optimizing a server so it performs worse than before.
So in the end, although our tool is excellent for creating a starting my.cnf, my old blog post about the ultimate my.cnf tuner tool, which claims that an expert human is the only safe way to do this, might be an evergreen truth.
PS: my favorite user feedback so far is this one:
Great job, very good results! Now please take it offline before I am rendered obsolete.