Please refer to source code to prove your argumentation. I'm not digging through source code for you; transactional atomicity is a well-known and thoroughly re

Please refer to source code to prove your argumentation. I'm not digging through source code for you; transactional atomicity is a well-known and thoroughly researched problem. Transactions in an ACID system are atomic by definition. They're designed in such a way that either an entire transaction occurs, or no part of a transaction occurs – in other words, it's not possible to partially apply a transaction, by design. There are a bunch of different approaches to implementing this. I'd guess that MySQL does something like write the complete set of modifications in a transaction to disk as a separate buffer, and only once the entire transaction is complete updating some associated metadata to add the transaction to the database. A power failure at any point will result in an uncommitted transaction, which will have no effect on the database. Here's the appropriate Wikipedia article for further reading -https://en.wikipedia.org/wiki/Atomicity_(database_systems) https://en.wikipedia.org/wiki/Atomicity_(database_systems) - lets suffice to say that if you are rejecting the idea that atomicity exists then I don't know what else to tell you. It's a core concept in information systems.