Chapter Assessment: Transactions

This review covers transactions in the booking service: what a transaction guarantees, the proxy behind @Transactional, propagation, isolation levels, rollback rules, the self-invocation trap, and optimistic and pessimistic locking. The bank holds 24 questions, and each attempt draws ten. Most questions describe a booking that went wrong, such as a declined payment, a failed email, or two requests for seat A12, and ask for the cause or the right repair. A few ask you to compute connections, versions, or wait times from the runs in the lessons