Hi, Thanks for awesome book. HibernateSpringBootOneToManyBidirectional has helper method removeBooks. ``` @Transactional public void deleteAllBooksOfAuthor() { Author author = authorRepository.findByName("Joana Nimar"); author.removeBooks(); // use removeBooks() helper } ``` But if you see carefully, it calls delete for each book entity. Can we optimize it somehow to call like IN queries instead? Also purpose of these helper methods is to call on managed entities or detached ones only?