title: What is the fastest way to find if a column has at least one NULL value in ORACLE database?
body: <p><code>select 1 from MYTABLE where MYDATE is null AND ROWNUM = 1;</code></p>
  
  <p>My tables have so much values, that request never ends…</p>
  
  <p>I try to find if a table has at least one <code>NULL</code> value in a particular column.</p>
  
  <p>Does <code>ROWNUM = 1</code> makes Oracle to stop at the first valid result? Or will it go thought the whole table? How to make it faster?</p>