public function getUnhealthyTable()
    {
        $app = Base::instance();
        $key = 'CACHE.db_unhealthy';
        if ($app->devoid($key)) {
            $tables = $this->getTables();
            $unhealthy = [];

            if ($tables) {
                foreach ($this->checkTables($tables) as $result) {
                    if (!in_array($result['Msg_text'], ['OK','Table is already up to date'])) {
                        $unhealthy[] = $result['Table'];
                    }
                }
            }

            $app->set($key, $unhealthy, 60);
        }

        return $app->get($key);
    }