[jasonlotito]

> Maybe the first request called a payment provider, the provider accepted it, and your process died before recording the result. Now your database cannot infer whether money moved.

This entire example is bad design. It's bad, bad design. I'm sorry, but if this is your example, you are doing it wrong in every way. There are ways to handle these sorts of things, well-known and well-established patterns. You are using none of these here.

I get it, it's an example, but it's a poor example. You should change it before someone assumes what you are talking about is sensible or reasonable in a production environment. Or at least put a warning.