What is the parameter max_questions and what is the maximum value it can reach when : update user set max_questions=0 where username= 'username' is specified
what is the maxumin limit .
... the 5.7 documentation for max_questions isn't too clear, how ever it stores the per-hour limit for the number of queries a user can execute.
0 is unlimited.
Here's a random site that explains a bit more about it: