[CH] refactor[#237]: Board-User-Like n+1 문제 해결

src/main/java/com/handong/cra/crawebbackend/board/domain/Board.java

@@ -7,6 +7,7 @@
 import com.handong.cra.crawebbackend.user.domain.User;
 import jakarta.persistence.*;
 import lombok.*;
+import org.hibernate.annotations.BatchSize;
 import org.hibernate.search.mapper.pojo.mapping.definition.annotation.FullTextField;
 import org.hibernate.search.mapper.pojo.mapping.definition.annotation.Indexed;
 
@@ -43,9 +44,11 @@ public class Board extends BaseEntity {
     @Setter
     private List<String> imageUrls = new ArrayList<>();
 
+    @BatchSize(size = 100)
     @OneToMany(mappedBy = "board", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<Comment> comments;
 
+    @BatchSize(size = 100)
     @ManyToMany(mappedBy = "likedBoards")
     private List<User> likedUsers = new ArrayList<>();
 

src/main/java/com/handong/cra/crawebbackend/board/repository/BoardRepository.java

@@ -18,9 +18,9 @@ public interface BoardRepository extends JpaRepository<Board, Long> {
 
     List<Board> findAllByCategoryAndDeletedFalse(Category category);
 
+    @Query("SELECT b FROM Board b JOIN FETCH b.user WHERE b.category = :category AND b.deleted = false")
     Page<Board> findAllByCategoryAndDeletedFalse(Category category, Pageable pageable);
 
-    @EntityGraph(attributePaths = {"likedUsers"})
     Optional<Board> findBoardByIdAndDeletedFalse(Long id);
 
     List<Board> findByCategory(Category category);

src/main/java/com/handong/cra/crawebbackend/user/domain/User.java

@@ -31,6 +31,7 @@ public class User extends BaseEntity {
     @Column(name = "github_id", nullable = false)
     private String githubId;
 
+
     private UserRoleSet roles;
 
     @Column(name = "student_id", unique = true, nullable = false)
@@ -46,7 +47,7 @@ public class User extends BaseEntity {
     @Column(name = "img_url")
     private String imgUrl;
 
-    @ManyToMany(fetch = FetchType.EAGER)
+    @ManyToMany(fetch = FetchType.LAZY)
     @JoinTable(
             name = "likes",
             joinColumns = @JoinColumn(name = "user_id"),

src/main/java/com/handong/cra/crawebbackend/user/domain/UserRoleSet.java

@@ -14,7 +14,7 @@
 @Embeddable
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 public class UserRoleSet {
-    @ElementCollection(fetch = FetchType.EAGER)
+    @ElementCollection(fetch = FetchType.LAZY)
     @CollectionTable(name = "roles", joinColumns = @JoinColumn(name = "user_id"))
     @Enumerated(EnumType.STRING)
     private Set<UserRoleEnum> roles = new HashSet<>();