title: ORACLE NOT NULL IN WHERE CLAUSE WITH NVL OPERATION
body: <p>I want to know which query is faster.</p>
  
  <p>ex:1</p>
  
  <pre><code>select comm
  from emp
  where comm is not null;
  </code></pre>
  
  <p>ex:2</p>
  
  <pre><code>select comm
  from emp
  where nvl(comm,'0') is not null;
  </code></pre>
  
  <p>Please consider the EMP table contains hundreds of thousands of records.</p>