In what situations does using the @Transactional annotation in Spring not provide the expected transactional behavior?

The @Transactional annotation in Spring may not ensure the expected transactional behavior in the following situations:

• Calling a method with @Transactional within the same class: if a method annotated with @Transactional is called from another method of the same class directly (without using proxies), the transaction will not be applied, as Spring uses proxies to manage transactions.

• Lack of proxy: if the class or method is not managed by the Spring container (for example, created manually via new), the annotation will not work.

• Unsupported exceptions: by default, transactions rollback only on unchecked exceptions (RuntimeException and Error). Checked exceptions do not trigger rollback unless explicitly specified.

• Propagation and isolation settings: incorrect configuration of transaction parameters can lead to unexpected behavior.

• Method marked as private or final: proxies cannot override such methods, and the transaction will not be applied.

For @Transactional to work correctly, it is important to call transactional methods through Spring proxies, use public methods, and properly configure exception handling.