MySQL hangs when I query specific tables after truncate I've observed this a couple of times now.
I truncated a table, and now anytime I do any SQL operation on that table, MYSQL client will stop responding. I can open a new client and query any other table. If I truncate another table while this is going on, it will also become unresponsive. It seems to take a very long time to "fix" itself.

Eventually, it does, and I can truncate the tables and run any other query operation against them.

Does anyone know why this would happen?
See answer on StackExchange and the bug is known and related to the autoincrement.
And if you don't only want to understand the issue, but fix it, see https://dba.stackexchange.com/a/146181/220459.
mysqladmin -u root proc
mysqladmin -u root kill xxx

where xxx is the first process that is hanging.