title: Is Sql Server's ISNULL() function lazy/short-circuited?
body: <p>TIs <code>ISNULL()</code> a lazy function?</p>
  
  <p>That is, if i code something like the following: </p>
  
  <p><code>SELECT ISNULL(MYFIELD, getMyFunction()) FROM MYTABLE</code></p>
  
  <p>will it always evaluate <code>getMyFunction()</code> or will it only evaluate it in the case where <code>MYFIELD</code> is actually null?</p>