What is generally used to store persistent data in online games - browser games/facebook apps, in particular?
I have used MySQL in web development before - but I've read that it's not very scalable, especially if many transactions are happening constantly (which is what will happen inside of a game).
I'm writing the back end in Node.js using Heroku, so it would be really nice if there were a Node package to go with it.
Any insight would be much appreciated.