title: Oracle (+) operator equal number
body: <p>I know what (+) operator does in this query:</p>
  
  <pre><code>SELECT 
     * 
  FROM
     TBL_TEST t, TBL_TEST_2 t2
  WHERE
     t.FIELD (+) = t2.FIELD;
  </code></pre>
  
  <p>But what (+) operator does in such query as:</p>
  
  <pre><code>SELECT 
     * 
  FROM
     TBL_TEST t
  WHERE
     t.FIELD (+) = 2;
  </code></pre>
  
  <p>I don't know...</p>
  
  <p>Can someone explain it?</p>