> Having a hosted system which behaves different than the underlying technology it's modelled on is not immediately clear. The realm of "things you don't know that you don't know" expands drastically with managed services.

So don't use managed services? They are expensive and the only thing that works consistently and well is the lock in, everything else is pretty iffy. Somehow people look at me like an idiot when I say this, but it's LESS effort to NOT use AWS and build everything yourself. I guess this seems impossible somehow, but at the scale you are ever going to operate it's not hard to just build a service to store and serve files (s3), and if you scale to the point where you can't build it easily, you will build it anyway because you can afford to hire enough engineers to build it and still save huge amounts of money. The same goes for every managed service offered on the cloud, they are not a good deal at any point, ever, for anybody.

> It's never been suggested that this is possible.

The gist of the article is they got a refund because they didn't bother to pay attention close enough to realize their queries were doing full table scans, and they didn't bother to pay close enough attention to realize this was causing the service to scale in capacity to an absurd degree.