title: Mysql temporarily suppress unique index
body: <p>I have a table with unique index on two columns, id_parent and sort_order to be precise</p>
  
  <pre><code>+----+-----------+------------+-------------+-------------+-------------+
  | id | id_parent | sort_order | some_data   | other_data  | more_data   |
  +----+-----------+------------+-------------+-------------+-------------+
  | 1  |         1 |          1 | lorem ipsum | lorem ipsum | lorem ipsum |
  | 2  |         1 |          2 | lorem ipsum | lorem ipsum | lorem ipsum |
  | 3  |         1 |          3 | lorem ipsum | lorem ipsum | lorem ipsum |
  +----+-----------+------------+-------------+-------------+-------------+
  </code></pre>
  
  <p>Now I want to update them, their data and their sort_order in one-go. sort_order would change from <code>1 - 2 - 3</code> to, for example <code>2 - 3 - 1</code>.</p>
  
  <p>But when I start running update statements, unique index block me, just as expected, saying that I can't have two rows with <code>id_parent = 1 and sort_order = 2</code>.
  Well, I could set it 4 for now, update other rows in correct order, and then set this one.
  But then, I would have to run an extra statement, and most probably add additional logic to my scripting language to determine correct order of updates.
  I also use ORM, and it becomes even more inconvinient.</p>
  
  <p>My question now, is there some method to make mysql temporarily ignore this index? Like starting a special transaction, in which indexes would be calculated only right before commiting it?</p>