title: Creating a MySQL index on a Varchar always makes 2 indexes?
body: <p>I have an <code>email</code> column in my table which is a <code>VARCHAR(255)</code>. Most emails would only be 40-50 characters long, and the rest of the characters are there just there for a rare case. Therefore, I want to only index the first 50 characters of the email column.</p>
  
  <p>I've tried to do it with this query:</p>
  
  <pre><code>ALTER TABLE  `users` ADD INDEX (email(50) )
  </code></pre>
  
  <p>However, that creates 2 indexes, one named <code>email</code> and the other <code>email_2</code>. The first index has no length limits, the second one has got the 50 character limit.</p>
  
  <p>Why is this? Is there any workaround or do I have no option but to index the full column?</p>