Wait for data to change

[Ben Clewett]

Dear MySQL,

I have an application which need to wait for some data to change, then 
act on this change.

I am polling the MySQL once a second using "SELECT ..."

I believe there is an alternate method where a thread can be made to 
wait for some change, therefore avoiding the expensive polling and 
improving performance.

If any member knows what this may be, I would be very interested.

Regards, Ben Clewett.