Spring Data & Transaction Management

Explain the JPA entity lifecycle and the role of the persistence context.

Implement declarative transaction management using @Transactional and explain key propagation levels (e.g., REQUIRED, REQUIRES_NEW).

Explain transaction isolation levels and their impact on data consistency issues like dirty reads and phantom reads.

Solve N+1 query problems using JOIN FETCH and @EntityGraph.

Implement efficient pagination and sorting for large datasets using Spring Data's Pageable interface.

Implement optimistic locking using @Version to prevent lost updates.

Diagnose transaction rollback scenarios, including the default behavior for checked vs. unchecked exceptions.

Explain how AOP proxies enable Spring's declarative transaction management and the self-invocation problem.