title: What's the concept of UPLEVEL operator?
body: <p>I'm not an expert in databases and I've just worked with MySQL database so far. I'm familiar with <code>SELECT</code>, <code>INSERT</code>, <code>UPDATE</code>, <code>DELETE</code> statements. Also as you know, there is lots of information about them in the internet. </p>
  
  <p>Recently I heard about something named <code>UPLEVEL</code> statement. I have no idea what the concept of it is, and I cannot find any good reference about it.</p>
  
  <p>Well, does anybody what's that exactly?</p>