🐞 JPA N+1 문제 - Fetch Join & EntityGraph

@Query("""
      SELECT p FROM Post p
      WHERE p.status = :status
      ORDER BY p.createdAt DESC, p.id DESC
      """)
Slice<Post> findPublishedPosts(@Param("status") PostStatus status, Pageable pageable);

Hibernate:
  select
    p1_0.id,
    p1_0.category_id,
    p1_0.content,
    -- 등등 필드들
  from
    post p1_0
  where
    p1_0.status=?
  order by
    p1_0.created_at desc,
    p1_0.id desc
  fetch
    first ? rows only
Hibernate:
  select
    c1_0.id,
    c1_0.created_at,
    -- 등등 필드들
  from
    category c1_0
  where
    c1_0.id=?
Hibernate:
  select
    c1_0.id,
    c1_0.created_at,
    -- 등등 필드들
  from
    category c1_0
  where
    c1_0.id=?
-- 이하 카테고리 개수만큼 반복

@Query("""
      SELECT p FROM Post p
      LEFT JOIN FETCH p.category
      WHERE p.status = :status
      ORDER BY p.createdAt DESC, p.id DESC
      """)
Slice<Post> findPublishedPosts(@Param("status") PostStatus status, Pageable pageable);

@EntityGraph(attributePaths = { "category" })
@Query("""
      SELECT p FROM Post p
      WHERE p.status = :status
      ORDER BY p.createdAt DESC, p.id DESC
      """)
Slice<Post> findPublishedPosts(@Param("status") PostStatus status, Pageable pageable);

Hibernate:
  select
    p1_0.id,
    c1_0.id,
    c1_0.created_at,
    -- 등등 필드들
  from
    post p1_0
  left join
    category c1_0
      on c1_0.id=p1_0.category_id
  where
    p1_0.status=?
  order by
    p1_0.created_at desc,
    p1_0.id desc