title: How to tune Informix database performance
body: <p>I want to how to do following general step:</p>
  
  <ol>
  <li>where to find slow SQL</li>
  <li>how to debug SQL (including functions)</li>
  <li>how to create index properly</li>
  <li>when using "update statistics", when should I use HIGH or LOW, and why?</li>
  </ol>
  
  <p>I am going to write a paper about this topic; any help is welcomed.</p>