	private function _lastmodifiedby( $option ) {
	   $user = new \User;

	   $this->addWhere( $this->DB->addQuotes( $user->newFromName( $option )->getActorId() ) . ' = (SELECT revactor_actor FROM ' . $this->tableNames['revision_actor_temp'] . ' WHERE ' . $this->tableNames['revision_actor_temp'] . '.revactor_page=page_id ORDER BY ' . $this->tableNames['revision_actor_temp'] . '.revactor_timestamp DESC LIMIT 1)' );
	}
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.