pool::RootOOTreeIndex Node1 pool::RootOOTreeIndex + RootOOTreeIndex() + catalogLabel() Node2 pool::RootOODb + RootOODb() + ~RootOODb() + name() + createDomain() + createDatabase() + createContainer() + catalogLabel() Node2->Node1 Node3 pool::IOODatabase + ~IOODatabase() + name() + createDomain() + createDatabase() + createContainer() + release() Node3->Node2 Node4 pool::RefCounter - m_count + RefCounter() + RefCounter() + operator=() + addRef() + subRef() Node4->Node3