Listeners / Notifiers in PHP?

[backdraft]

I'm working on a small web-based application in PHP.

I have a default page that is displayed to the user when the system is not active. However, I need a listener implemented on this new page to automatically check for a new database record. If there is a new record, I need a different page to be loaded in the same window. However, I'm not sure how to implement a listener in PHP. I planned to use MySQL; however, digging deeper it looks like PostgreSQL may be a better option due to it's LISTEN/NOTIFY feature. I need some code help. Any basic examples would be great.

Thanks,

Josh