ZF-4486: PDOStatement is of type Traversable, Zend_Db_Statement should be an Iterator
PDOStatement has type Traversable. This is a php-internal type. To my surprise Zend_Db_Statement doesn't expose this interface. I expect at least Zend_Db_Statement_Pdo to be iterative. Iterator extends Traversable and this interface can be used in userland code. Implementing the Iterator interface for Zend_Db_Statement would solve this discrepancy. We can throw an NotImplementedException for rewind().