title: EJB 3.0 - Nested Transaction != Requires New?
body: <p>I just read the Transactions Chapter (10) of "Mastering EJB 3.0" and now I'm confused about nested transactions.</p>
  
  <p>The book says </p>
  
  <blockquote>
    <p>"The EJB-defined transaction manager does not
    support nested transactions; it requires support for only flat transactions." (Site 278, Note)</p>
  </blockquote>
  
  <p>This fact is described not only by this book, I found this statement in other books / websites.</p>
  
  <p>But if I call a "Requires New" annotated Method from a, let's say "Required" annotated Methode, what I have is a nested transaction, isn't it? I can roll back the inner transaction or commit it, without affecting the outer transaction.
  And if I want the outer Transaction to be aborted, I throw an EJBException back and the whole transaction will be rolled back. </p>
  
  <p>So is it just that this behavior is <strong>not required</strong> by the EJB 3.0 specification or have i misunderstood something? I just can't get the difference between nested transactions and the described behavior.</p>
  
  <p>Regards
  Norman</p>