title: MySQL table cache hit rate
body: <p>Could you, please, explain what is the meaning of the following MySQL metric:</p>
  
  <blockquote>
    <p>table cache hit rate = open_tables / opened_tables.</p>
  </blockquote>
  
  <p>As I understand open_tables is the current value of opened tables and opened_tables is a counter and there is no any correlation between these two status variables.</p>