This seems to overlook really hard part where joins become important which is for things that need to transactional, such as how much money I have in my bank ac

This seems to overlook really hard part where joins become important which is for things that need to transactional, such as how much money I have in my bank account. I might not care if it takes 30 seconds for my change of name to propagate to 300 different papers I have written, but it is crucially important that I have only one total for my bank account and that it is never allowed to fall below zero (simplistically).