title: What the difference between mysql and mysql2 gem
body: <p>I used to work with the <code>mysql</code> gem, but often nowadays I hear about the <code>mysql2</code> gem. Also, it is included in the <strong>Gemfile</strong> by default in <code>Rails 3.0.x</code>.</p>
  
  <p>What is the difference and advantages of using the <code>mysql2</code> gem?</p>