title: An alternative to deprecated addKey() method in Magento?
body: <p>I am trying to add an index for a column over Magento data setup script.</p>
  
  <pre><code>/** @var Mage_Eav_Model_Entity_Setup $installer */
  $installer = $this;
  $installer-&gt;startSetup();
  $installer
      -&gt;getConnection()
      -&gt;addKey(
          $installer-&gt;getTable('enterprise_rma/rma'),
          'IDX_EXPORT_DATE',
          'export_date'
      );
  </code></pre>
  
  <p>However our inspection tool complains:</p>
  
  <pre><code>The method Varien_Db_Adapter_Pdo_Mysql::addKey() has been deprecated with message: since 1.5.0.0
  </code></pre>
  
  <p>What I can use instead of addKey() in this case?</p>