What problem occurs when calling an @Transactional method from another method of the same class?

When calling a method annotated with @Transactional from another method within the same class directly (i.e., without using Spring's proxy), the transactional behavior is not applied. This occurs because Spring uses proxies to manage transactions, and an internal method call does not go through the proxy but is called directly, bypassing the transaction management mechanisms. As a result, the transaction will not be created or managed as expected.