Pitfalls of isolation levels in distributed databases

This post explains the trade-offs of different isolation levels (Serializable, RepeatableRead, SnapshotRead/MVCC, ReadCommitted, ReadUncommitted) in distributed databases. It uses bank and retail use cases to illustrate the practical implications of each level, particularly concerning contention, deadlocks, and scalability. The post highlights that while Serializable offers theoretical purity, it's often impractical for scalable systems. SnapshotRead (MVCC) is presented as beneficial for read-only workloads, while ReadCommitted with explicit locking is suggested as a practical approach for write-heavy transactions. It also touches upon the complexities of distributed transactions and the overhead of two-phase commit (2PC).