How do I update a web app to change in mysql db?

I want to alert a number of connected users to a change in the database without having the end user polling mysql. Is there a way to trigger a client update from the server side without moving long polling down the stack? I'm using PHP, Javascript, and MySQL. ~70 clients need to be updated at once and was hoping to have a b开发者_如何学JAVAetter response time and lower hits to the web and db server than AJAX/COMET allows.

Thanks,

T

You may want to look into HTML5 web sockets too which would be a little more resource efficient than tons of Ajax calls.