'Must be implemented by subclasses to accommodate DDL executions.
"connection" is the raw unwrapped DBAPI connection.   "value"
is True or False.  when True, the connection should be configured
such that a DDL can take place subsequently.  when False,
a DDL has taken place and the connection should be resumed
into non-autocommit mode.'

def set_ddl_autocommit(self, connection, value):

    raise NotImplementedError()
