Quora keeps Questions and the Interest Graph in RAM. Wait, what?!
Adam Rifkin stashed this in Quora!
Mother of God:
Q: Would Quora have an expensive Amazon bill if it didn't allow posting of images (i.e. was just text)?
Answer from Adam D'Angelo, Quora Founder: "Yes. Images are a very small percentage of our overall costs.
"Much more expensive is data that needs to be kept in ram, like questions and the graph of what each person is interested in.
"Also, computation to generate each page adds up to much more than the storage for images. Because images don't need to be in ram and don't require computation (we just read an image in and send it out) and we don't have the quantity of images that a personal photo sharing site would have, they don't contribute too much to our total costs."
Is it really necessary to store all of that information in RAM?
Mother of RAM!