I would really prefer to stick with a PHP implementation for now, but if it's really going to be SIGNIFICANTLY more efficient I am considering switching to Node.js. I want to design an app that would involve users connecting directly with each other, sending each other information and making sure the other hasn't disconnected.
Right now, my plan is to use a MySQL database and have the clients sending AJAX requests to the server to update a row in a table created for that specific event. Hardware-wise, would sockets be somehow better? Is there a good alternative to MySQL for this in general? Note that I WILL have to use MySQL for data tracking and things of that nature anyway.
Disclaimer: I don't actually know what sockets are or how they work, I just know roughly how to implement them and am deciding whether to look into them further.