title: How to mark a persistence-unit as default in JPA (hibernate)?
body: <p>I read a few threads on setting a one out of n persistence-unit in JPA as default. But the usage of hibernate.default_schema seems to be vague.</p>
  
  <p>However, I want to achieve the following.</p>
  
  <ul>
  <li>Have one default <code>&lt;persistence-unit name="myMainPU"&gt; ... &lt;/persistence-unit&gt;</code></li>
  <li>Have one or more additional <code>&lt;persistence-unit name="auxilliaryPU"&gt; ... &lt;/persistence-unit&gt;</code></li>
  <li>I don't want to annotate my injected EntityManagers with the name attribute. E.g. not like this <code>@Persistence(unitName="myMainPU")</code> for the default persistence unit. Should be simply like this <code>@Persistence</code>.</li>
  <li>I want to annotate my auxilliary PUs with the unitName attribute. E.g. <code>@Persistence(unitName="auxilliaryPU")</code> </li>
  </ul>
  
  <p>How does one achive that? I use Hibernate 4+ and could also accept a proprietary solution.</p>
  
  <p>Thanks.</p>