The classic example for a transaction is withdrawing money from a savings account and depositing it to a checking account in the same bank.
Yet I have the suspicion that DB transactions are actually not used for such examples, but rather that eventual consistency is achieved with a a journaling system that reconciles inconsistencies at the end of the day. I imagine that transactions are used for a single update (withdrawal/deposit).
What is the best practice? I realize that here is no single answer, but I wonder what is commonly done.
(This asks the same question, but about distributed systems. I am asking what is done within a single bank.)