title: MySQL applys global variables to opened session
body: <p>I've found that session variables have priority over global variables.</p>
  <p>Is it possible to apply global variables which is set by &quot;set global&quot; query to opened session so make local one to same with global one?</p>
  <p>Or, is there any way to wait all opened session finish their tasks, and make sleeping session to reconnect?</p>