Why Blockchains Don’t Suck, and the Perils of Distributed Databases
Coral Health

“if we submit multiple parallel value decrement transactions (e.g. on financial account balances), with weak isolation levels, we can easily end up with a negative balance.”

Just a newbie question: how an application using blockchains avoid this?

My fist assumption is a block only store the delta, like {account: 123, transction: abcd, amount: -12}… is it correct? How can we store a “snapshot” of current balance? What kind of “constraints” we can use with blockchain?