규호 ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=624fda4... ) *updated* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiOGVlOGYyMmM4... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16005?atlOrigin=eyJpIjoiOGVlOG... ) HHH-16005 ( https://hibernate.atlassian.net/browse/HHH-16005?atlOrigin=eyJpIjoiOGVlOG... ) @BatchSize with @ManyToMany does not work as expected when migrating 5 -> 6 ( https://hibernate.atlassian.net/browse/HHH-16005?atlOrigin=eyJpIjoiOGVlOG... ) Change By: 규호 ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=624fda4... ) from [https://discourse.hibernate.org/t/batchsize-with-manytomany-does-not-work...] I have the following entities. Entity Models: {code:java}@Entity @Getter @Setter public class Article { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int id; private String categoryId; @BatchSize(size = 20) @ManyToMany private List<Tag> tags = new ArrayList<>(); }{code} {code:java}@Entity @Getter @NoArgsConstructor public class Tag { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @Column(unique = true) private String name; public Tag (String name) { this.name = name; } } {code} And DTO: {noformat}@Getter public class ArticleResponseDto { private final int id; private final List<TagDto> tags; public ArticleResponseDto(Article article) { this.id = article.getId(); this.tags = article.getTags().stream() .map(TagDto::new) .toList(); } } @Getter class TagDto { private final String name; public TagDto(Tag tag) { this.name = tag.getName(); } }{noformat} In Hibernate 5.6.14, when querying articles, it generated queries : {noformat}Hibernate: select article0_.id as id1_0_, article0_.category_id as category2_0_ from article article0_ order by article0_.id DESC limit ? Hibernate: select tags0_.article_id as article_1_1_1_, tags0_.tags_id as tags_id2_1_1_, tag1_.id as id1_2_0_, tag1_.name as name2_2_0_ from article_tags tags0_ inner join tag tag1_ on tags0_.tags_id=tag1_.id where tags0_.article_id in (?, ?, ?, ?, ?){noformat} However In Hibernate 6.1.6: {noformat}Hibernate: select t1_0.article_id,t1_1.id,t1_1.name from article_tags t1_0 join tag t1_1 on t1_1.id=t1_0.tags_id where t1_0.article_id in(?,?,?,?,?) Hibernate: select t1_0.article_id,t1_1.id,t1_1.name from article_tags t1_0 join tag t1_1 on t1_1.id=t1_0.tags_id where t1_0.article_id in(?,?) Hibernate: select t1_0.article_id,t1_1.id,t1_1.name from article_tags t1_0 join tag t1_1 on t1_1.id=t1_0.tags_id where t1_0.article_id in(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?){noformat} Hibernate 6.1.6 generated queries 2 more and binded data in each query were article-id that had empty tag list. And the values in IN clause at the last query was always generated as much as the size of {{@BatchSize}}. Test Code: {noformat}@SpringBootTest @Transactional class TestServiceTest { @Autowired private EntityManager entityManager; @BeforeEach void fixture() { List<Tag> tags = List.of(new Tag("t1"), new Tag("t2"), new Tag("t3")); List<Tag> tags2 = List.of(new Tag("t4"), new Tag("t5")); Article article = new Article(); Article article2 = new Article(); Article article3 = new Article(); Article article4 = new Article(); Article article5 = new Article(); article.setTags(tags); article3.setTags(tags2); tags.forEach(entityManager::persist); tags2.forEach(entityManager::persist); entityManager.persist(article); entityManager.persist(article2); entityManager.persist(article3); entityManager.persist(article4); entityManager.persist(article5); entityManager.flush(); entityManager.clear(); } @Test void test() { Query query = entityManager.createQuery("select a from Article a"); List<Article> tech = query.setMaxResults(20).getResultList(); tech.stream() .map(ArticleResponseDto::new) .toList(); } }{noformat} I expected executing queries same in both version, it wasn't. h3. Reproducer reproducer: [https://github.com/chlrbgh89/hibernate-batch-size-bug|https://github.com/...] reproducer Hibernate version is {{6.1.6.Final}} If you want to downgrade version to {{5.6.14.Final}}, uncomment this code in {{build.gradle}} {code:groovy}//configurations.configureEach { //    resolutionStrategy.eachDependency {details -> //        if(details.requested.name == 'hibernate-core') { //            details.useTarget group: 'org.hibernate', name:'hibernate-core-jakarta', version: '5.6.14.Final' //        } //    } //}{code} ( https://hibernate.atlassian.net/browse/HHH-16005#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16005#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100213- sha1:1fa7b87 )