title: Grails add domain field as database index
body: <p>I'm using grails 1.2.2 and 1.3.7 in my project.
  I want to add an index to the domain's table.</p>
  
  <pre><code>class Test {
  String name
  String surname
  
  static mapping = {
  name column: 'name', index: 'test_dx'
  surname column: 'surname', index: 'test_dx'
  }
  </code></pre>
  
  <p>}</p>
  
  <p>I tried with the two version of grails and with dbCreate = "create" or dbCreate = "create-drop" or dbCreate = "update" (is the one I want to use) but no "custom index" created.</p>