Pingovat DB každou sekundu není ideální způsob, jak toho dosáhnout; můžete implementovat kombinaci spouštěčů DB a HTML5 websockets/push notifications:https://html5hacks.com/blog/2013/04/21/push-notifications-to-the-browser-with-server-sent-events/
https://www.abrandao.com/2013/06/25/websockets-using-modern-html5-technology-for-true-server-push/
https://pusher.com/tutorials/html5_realtime_push_notifications