N + 1 쿼리 횟수

안녕하세요 강의 너무 잘 듣고 있습니다.

"간단한 주문 조회 V2: 엔티티를 DTO로 변환" 강의를 듣던 중 궁금한 점이 생겨 질문 드립니다.

Order 엔티티를 SimpleOrderDto로 변환하는 과정에서 아래 조건으로 인해 샘플 데이터 2개 기준 총 5(1 + 2 + 2)번의 쿼리가 날아간다고 이해했습니다.

• order -> member 지연 로딩 조회 N번

• order -> delivery 지연 로딩 조회 N번

근데 저는 order -> delivery 쿼리 이후에 order를 찾는 쿼리가 한번 더 날아가는 것처럼 보입니다. 총 7번의 쿼리가 발생하는 것 같은데 무엇 때문인지 설명해주실 수 있을까요?

코드와 콘솔 로그는 아래 첨부했습니다. 감사합니다.

// Order 엔티티
    @Id
    @GeneratedValue
    @Column(name = "order_id")
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "member_id")
    private Member member;

    @OneToMany(mappedBy = "order", cascade = CascadeType.ALL)
    private List<OrderItem> orderItems = new ArrayList<>();

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "delivery_id")
    private Delivery delivery;

    private LocalDateTime orderDate;

    @Enumerated(EnumType.STRING)
    private OrderStatus status; // 주문상태

// Delivery 엔티티

    @Id
    @GeneratedValue
    @Column(name = "delivery_id")
    private Long id;

    @JsonIgnore
    @OneToOne(mappedBy = "delivery", fetch = FetchType.LAZY)
    private Order order;

    @Embedded
    private Address address;

    @Enumerated(EnumType.STRING)
    private DeliveryStatus status; // READY, COMP

// OrderSimpleApiController

    @GetMapping("/api/v2/simple-orders")
    public List<SimpleOrderDTO> ordersV2() {
        List<Order> orders = orderRepository.findAll(new OrderSearch());

        return orders.stream()
                .map(SimpleOrderDTO::new)
                .toList();
    }

    @Data
    static class SimpleOrderDTO {

        private Long orderId;
        private String name;
        private LocalDateTime orderDate;
        private OrderStatus orderStatus;
        private Address address;

        public SimpleOrderDTO(Order order) {
            this.orderId = order.getId();
            this.name = order.getMember().getName(); // Lazy 초기화
            this.orderDate = order.getOrderDate();
            this.orderStatus = order.getStatus();
            this.address = order.getDelivery().getAddress(); // Lazy 초기화
        }

    }

2024-04-09T13:27:53.982+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        o1_0.order_id,
        o1_0.delivery_id,
        o1_0.member_id,
        o1_0.order_date,
        o1_0.status 
    from
        orders o1_0 
    join
        member m1_0 
            on m1_0.member_id=o1_0.member_id
2024-04-09T13:27:53.984+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636873984|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select o1_0.order_id,o1_0.delivery_id,o1_0.member_id,o1_0.order_date,o1_0.status from orders o1_0 join member m1_0 on m1_0.member_id=o1_0.member_id|select o1_0.order_id,o1_0.delivery_id,o1_0.member_id,o1_0.order_date,o1_0.status from orders o1_0 join member m1_0 on m1_0.member_id=o1_0.member_id
2024-04-09T13:27:54.005+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        m1_0.member_id,
        m1_0.city,
        m1_0.street,
        m1_0.zipcode,
        m1_0.name 
    from
        member m1_0 
    where
        m1_0.member_id=?
2024-04-09T13:27:54.007+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636874007|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select m1_0.member_id,m1_0.city,m1_0.street,m1_0.zipcode,m1_0.name from member m1_0 where m1_0.member_id=?|select m1_0.member_id,m1_0.city,m1_0.street,m1_0.zipcode,m1_0.name from member m1_0 where m1_0.member_id=1
2024-04-09T13:27:54.012+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        d1_0.delivery_id,
        d1_0.city,
        d1_0.street,
        d1_0.zipcode,
        d1_0.status 
    from
        delivery d1_0 
    where
        d1_0.delivery_id=?
2024-04-09T13:27:54.013+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636874013|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select d1_0.delivery_id,d1_0.city,d1_0.street,d1_0.zipcode,d1_0.status from delivery d1_0 where d1_0.delivery_id=?|select d1_0.delivery_id,d1_0.city,d1_0.street,d1_0.zipcode,d1_0.status from delivery d1_0 where d1_0.delivery_id=1
2024-04-09T13:27:54.016+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        o1_0.order_id,
        o1_0.delivery_id,
        o1_0.member_id,
        o1_0.order_date,
        o1_0.status 
    from
        orders o1_0 
    where
        o1_0.delivery_id=?
2024-04-09T13:27:54.016+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636874016|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select o1_0.order_id,o1_0.delivery_id,o1_0.member_id,o1_0.order_date,o1_0.status from orders o1_0 where o1_0.delivery_id=?|select o1_0.order_id,o1_0.delivery_id,o1_0.member_id,o1_0.order_date,o1_0.status from orders o1_0 where o1_0.delivery_id=1
2024-04-09T13:27:54.018+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        m1_0.member_id,
        m1_0.city,
        m1_0.street,
        m1_0.zipcode,
        m1_0.name 
    from
        member m1_0 
    where
        m1_0.member_id=?
2024-04-09T13:27:54.019+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636874019|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select m1_0.member_id,m1_0.city,m1_0.street,m1_0.zipcode,m1_0.name from member m1_0 where m1_0.member_id=?|select m1_0.member_id,m1_0.city,m1_0.street,m1_0.zipcode,m1_0.name from member m1_0 where m1_0.member_id=2
2024-04-09T13:27:54.020+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        d1_0.delivery_id,
        d1_0.city,
        d1_0.street,
        d1_0.zipcode,
        d1_0.status 
    from
        delivery d1_0 
    where
        d1_0.delivery_id=?
2024-04-09T13:27:54.020+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636874020|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select d1_0.delivery_id,d1_0.city,d1_0.street,d1_0.zipcode,d1_0.status from delivery d1_0 where d1_0.delivery_id=?|select d1_0.delivery_id,d1_0.city,d1_0.street,d1_0.zipcode,d1_0.status from delivery d1_0 where d1_0.delivery_id=2
2024-04-09T13:27:54.021+09:00 DEBUG 12424 --- [nio-8080-exec-2] org.hibernate.SQL                        : 
    select
        o1_0.order_id,
        o1_0.delivery_id,
        o1_0.member_id,
        o1_0.order_date,
        o1_0.status 
    from
        orders o1_0 
    where
        o1_0.delivery_id=?
2024-04-09T13:27:54.021+09:00  INFO 12424 --- [nio-8080-exec-2] p6spy                                    : 1712636874021|0|statement|connection 7|url jdbc:h2:tcp://localhost/~/jpashop_v2|select o1_0.order_id,o1_0.delivery_id,o1_0.member_id,o1_0.order_date,o1_0.status from orders o1_0 where o1_0.delivery_id=?|select o1_0.order_id,o1_0.delivery_id,o1_0.member_id,o1_0.order_date,o1_0.status from orders o1_0 where o1_0.delivery_id=2