title: Should Plan cost be less than 100?
body: <p>I know lesser the cost faster will be query. But recently i came  across the statement that cost should always be less than 100 . Is that true ?</p>
  
  <p>As per my understanding cost is proportioal to (IO operation/CPU usage/network resources used). Which means when i say cost is high ,any/all of  these three operations i.e IO operation/CPU usage/network resources  usage can be high . Is that correct ?</p>