Transactions

ACID, 2PL, OCC, MVCC, 2PC, Spanner, Saga, Outbox; XA limitations; coordination-avoiding correctness; Newman's "just say no" to 2PC during migration

Atomic write + publish without 2PC; relay process; CDC; data liberation patterns; DDD: two wrong approaches + correct approach; NoSQL embedding; pull vs push relay

Distributed transactions via local transactions + compensations; 8 saga type taxonomy; semantic vs implementation coupling; orchestration/choreography trade-offs; DDD: saga vs process manager distinction; stateless/stateful saga; process manager as aggregate; Newman: backward/forward recovery, semantic rollbacks, step reordering, team-based coordination choice

ACID, isolation levels (dirty reads, read skew, write skew, phantoms), MVCC, SSI, actual serial execution, 2PL