Learning MySQL Internals via bug reports
By realneel on Sep 23, 2008
One example is Bug#32149 Long semaphore wait for adaptive hash latch. The bug synopsis could very well have been Why are global locks in a storage engine such a BAD idea. There is lots of useful information about this and the workaround MySQL server uses to work with storage engines that do.. Interesting!
Do you know of any other interesting bugs that document MySQL internals?