title: MySQL doesn't use indexes when query over BIT field using bitwise functions
body: <p>I have a field of type BIT in my MySQL table. I want to store statuses of the record using bit value, for example:</p>
  
  <pre><code>1 = status1
  2 = status2
  4 = status3
  8 = status4
  </code></pre>
  
  <p>Each record can have many statuses at once. For status1 and status3 the value will be 1 + 4 = 5. I can query table for all records with status3 using:</p>
  
  <pre><code>SELECT * 
    FROM `table` 
   WHERE `statuses` &amp; 4 
  </code></pre>
  
  <p>I have index on <code>statuses</code>, but <code>EXPLAIN</code> tells that no index is used. Can I use index in such situation?</p>
  
  <p>P.S. Using separate many-to-many linking table is more normalized solution, but I'd like to have more 'flat' structure for this.</p>