5.1 ~ 5.3: [트랜잭션과 잠금](https://velog.io/@fortice/MySQL-%ED%8A%B8%EB%9E%9C%EC%9E%AD%EC%85%98-%EC%9E%A0%EA%B8%88Lock) 5.4: [격리수준](https://velog.io/@fortice/MySQL-%EA%B2%A9%EB%A6%AC-%EC%88%98%EC%A4%80)
