This approach only works if your logic is codable in SQL format in the way this trivial balance change can be. If the change is happening in app business logic,

This approach only works if your logic is codable in SQL format in the way this trivial balance change can be. If the change is happening in app business logic, this is always going to be a problem. The fact the balance+=25 type approach works is kind of a hack, and I don't think Aphyr is wrong to call it "corrupted" (in this specific example, in one transaction, you could say that it is inconsistent - but you only need a few inconsistent operations in the same place and suddenly your data is complete rubbish). This feels a bit like handwaving the problem away, to me. Yes, InnoDB has the problem, but with that backend you can set SERIALIZABLE isolation. You can't do that in Galera. So if you don't have the option of rewriting the SQL (either because it's not your SQL, or there is no SQL alternative available) then you're screwed.