Here are the that changed how I write data access code:
If two users try to update the same inventory record concurrently, the first transaction succeeds and increments the version number. The second transaction fails with an OptimisticLockException , which can be safely caught and retried at the application level. Pessimistic Locking High-performance Java Persistence.pdf
Fetching raw DTOs via JPQL or native queries allows the persistence provider to skip memory-heavy entity lifecycle management and dirty-checking, radically reducing heap allocation. Second-Level (L2) Caching Here are the that changed how I write