I had a really interesting conversation on facebook today with a friend I knew from school. We are both professional developers now, and we occasionally exchange ideas on software development. I feel that this particular conversation was worth documenting for posterity because of the natural progression of ideas. I think that the overall conversation simplifies  a lot of very complicated ideas into a narrative structure.

Edgar: What’s your opinion on this hilarious discussion?

Me: I’ve actually seen this. We use both MongoDB and MySQL at work. There is a religious war between different teams, here.

Edgar: I think MySQL is better in situations where you need reliability above all else.

Me: You can get reliability with MongoDB. You just don’t have transactions across documents. Databases have transactions across tables. MongoDB only supports transactions for a single document. That issue is important when you design your application.

Me: The problem is…