title: How to use Explain Plan to optimize queries?
body: <p>I have been tasked to optimize some sql queries at work. Everything I have found points to using Explain Plan to identify problem areas. The problem I can not find out exactly what explain plan is telling me. You get Cost, Cardinality, and bytes. </p>
  
  <p>What do this indicate, and how should I be using this as a guide. Are low numbers better? High better? Any input would be greatly appreciated. </p>
  
  <p>Or if you have a better way to go about optimizing a query, I would be interested.</p>