Database Transactions

When to use

• The user hits InnoDB deadlocks or deadlock errors under load, lost updates, or inconsistent reads, and wants to handle and retry them when multiple requests write the same rows concurrently.
• The user needs to pick or reason about an isolation level (READ COMMITTED, REPEATABLE READ, SERIALIZABLE), use a savepoint for partial rollback, or fix a phantom/non-repeatable read.
• The user performs multiple related writes (transfer funds, create order plus line items) that must commit together or not at all.

When NOT to use