[JPA] 페이징 처리 성능 최적화하기

문제 배경

내가 작성한 리뷰를 조회하는 API를 스프링 데이터 JPA의 페이징 처리를 통해 구현했다.

현재 API를 호출했을 때 실행되는 SQL 쿼리문을 보면 N+1 문제가 발생한다.

• 실행되는 SQL 쿼리문

2024-02-11 18:31:29.479  INFO 29300 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2024-02-11 18:31:29.479  INFO 29300 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2024-02-11 18:31:29.483  INFO 29300 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 4 ms
2024-02-11 18:31:29.491  INFO 29300 --- [nio-8080-exec-1] t.OTTify.oauth.jwt.JwtAuthFilter         : checkAccessTokenAndAuthentication() 호출
2024-02-11 18:31:29.491  INFO 29300 --- [nio-8080-exec-1] tavebalak.OTTify.oauth.jwt.JwtService    : extractAccessToken() 호출
Hibernate: 
    select
        review0_.review_id as review_i1_10_,
        review0_.created_at as created_2_10_,
        review0_.updated_at as updated_3_10_,
        review0_.content as content4_10_,
        review0_.genre as genre5_10_,
        review0_.like_counts as like_cou6_10_,
        review0_.program_id as program_8_10_,
        review0_.rating as rating7_10_,
        review0_.user_id as user_id9_10_ 
    from
        review review0_ 
    left outer join
        `user` user1_ 
            on review0_.user_id=user1_.user_id 
    where
        user1_.user_id=? 
    order by
        review0_.created_at asc,
        review0_.created_at asc limit ?
2024-02-11 18:31:29.562  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889562 | took 7ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select review0_.review_id as review_i1_10_, review0_.created_at as created_2_10_, review0_.updated_at as updated_3_10_, review0_.content as content4_10_, review0_.genre as genre5_10_, review0_.like_counts as like_cou6_10_, review0_.program_id as program_8_10_, review0_.rating as rating7_10_, review0_.user_id as user_id9_10_ from review review0_ left outer join `user` user1_ on review0_.user_id=user1_.user_id where user1_.user_id=? order by review0_.created_at asc, review0_.created_at asc limit ?
select review0_.review_id as review_i1_10_, review0_.created_at as created_2_10_, review0_.updated_at as updated_3_10_, review0_.content as content4_10_, review0_.genre as genre5_10_, review0_.like_counts as like_cou6_10_, review0_.program_id as program_8_10_, review0_.rating as rating7_10_, review0_.user_id as user_id9_10_ from review review0_ left outer join `user` user1_ on review0_.user_id=user1_.user_id where user1_.user_id=1 order by review0_.created_at asc, review0_.created_at asc limit 11;
Hibernate: 
    select
        reviewrevi0_.review_id as review_i2_11_0_,
        reviewrevi0_.review_review_tag_id as review_r1_11_0_,
        reviewrevi0_.review_review_tag_id as review_r1_11_1_,
        reviewrevi0_.review_id as review_i2_11_1_,
        reviewrevi0_.review_tag_id as review_t3_11_1_ 
    from
        review_review_tag reviewrevi0_ 
    where
        reviewrevi0_.review_id=?
2024-02-11 18:31:29.587  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889587 | took 6ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewrevi0_.review_id as review_i2_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_1_, reviewrevi0_.review_id as review_i2_11_1_, reviewrevi0_.review_tag_id as review_t3_11_1_ from review_review_tag reviewrevi0_ where reviewrevi0_.review_id=?
select reviewrevi0_.review_id as review_i2_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_1_, reviewrevi0_.review_id as review_i2_11_1_, reviewrevi0_.review_tag_id as review_t3_11_1_ from review_review_tag reviewrevi0_ where reviewrevi0_.review_id=4;
Hibernate: 
    select
        reviewtag0_.review_tag_id as review_t1_12_0_,
        reviewtag0_.name as name2_12_0_ 
    from
        review_tag reviewtag0_ 
    where
        reviewtag0_.review_tag_id=?
2024-02-11 18:31:29.601  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889601 | took 5ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id=?
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id=3;
Hibernate: 
    select
        user0_.user_id as user_id1_14_0_,
        user0_.created_at as created_2_14_0_,
        user0_.updated_at as updated_3_14_0_,
        user0_.average_rating as average_4_14_0_,
        user0_.code as code5_14_0_,
        user0_.email as email6_14_0_,
        user0_.grade as grade7_14_0_,
        user0_.nick_name as nick_nam8_14_0_,
        user0_.profile_photo as profile_9_14_0_,
        user0_.role as role10_14_0_,
        user0_.social_type as social_11_14_0_,
        user0_.review_counts as review_12_14_0_ 
    from
        `user` user0_ 
    where
        user0_.user_id=?
2024-02-11 18:31:29.612  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889612 | took 10ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select user0_.user_id as user_id1_14_0_, user0_.created_at as created_2_14_0_, user0_.updated_at as updated_3_14_0_, user0_.average_rating as average_4_14_0_, user0_.code as code5_14_0_, user0_.email as email6_14_0_, user0_.grade as grade7_14_0_, user0_.nick_name as nick_nam8_14_0_, user0_.profile_photo as profile_9_14_0_, user0_.role as role10_14_0_, user0_.social_type as social_11_14_0_, user0_.review_counts as review_12_14_0_ from `user` user0_ where user0_.user_id=?
select user0_.user_id as user_id1_14_0_, user0_.created_at as created_2_14_0_, user0_.updated_at as updated_3_14_0_, user0_.average_rating as average_4_14_0_, user0_.code as code5_14_0_, user0_.email as email6_14_0_, user0_.grade as grade7_14_0_, user0_.nick_name as nick_nam8_14_0_, user0_.profile_photo as profile_9_14_0_, user0_.role as role10_14_0_, user0_.social_type as social_11_14_0_, user0_.review_counts as review_12_14_0_ from `user` user0_ where user0_.user_id=1;
Hibernate: 
    select
        program0_.program_id as program_1_7_0_,
        program0_.average_rating as average_2_7_0_,
        program0_.created_year as created_3_7_0_,
        program0_.poster_path as poster_p4_7_0_,
        program0_.review_count as review_c5_7_0_,
        program0_.title as title6_7_0_,
        program0_.tm_db_program_id as tm_db_pr7_7_0_,
        program0_.type as type8_7_0_ 
    from
        program program0_ 
    where
        program0_.program_id=?
2024-02-11 18:31:29.636  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889636 | took 22ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select program0_.program_id as program_1_7_0_, program0_.average_rating as average_2_7_0_, program0_.created_year as created_3_7_0_, program0_.poster_path as poster_p4_7_0_, program0_.review_count as review_c5_7_0_, program0_.title as title6_7_0_, program0_.tm_db_program_id as tm_db_pr7_7_0_, program0_.type as type8_7_0_ from program program0_ where program0_.program_id=?
select program0_.program_id as program_1_7_0_, program0_.average_rating as average_2_7_0_, program0_.created_year as created_3_7_0_, program0_.poster_path as poster_p4_7_0_, program0_.review_count as review_c5_7_0_, program0_.title as title6_7_0_, program0_.tm_db_program_id as tm_db_pr7_7_0_, program0_.type as type8_7_0_ from program program0_ where program0_.program_id=1;
Hibernate: 
    select
        reviewrevi0_.review_id as review_i2_11_0_,
        reviewrevi0_.review_review_tag_id as review_r1_11_0_,
        reviewrevi0_.review_review_tag_id as review_r1_11_1_,
        reviewrevi0_.review_id as review_i2_11_1_,
        reviewrevi0_.review_tag_id as review_t3_11_1_ 
    from
        review_review_tag reviewrevi0_ 
    where
        reviewrevi0_.review_id=?
2024-02-11 18:31:29.643  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889643 | took 5ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewrevi0_.review_id as review_i2_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_1_, reviewrevi0_.review_id as review_i2_11_1_, reviewrevi0_.review_tag_id as review_t3_11_1_ from review_review_tag reviewrevi0_ where reviewrevi0_.review_id=?
select reviewrevi0_.review_id as review_i2_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_0_, reviewrevi0_.review_review_tag_id as review_r1_11_1_, reviewrevi0_.review_id as review_i2_11_1_, reviewrevi0_.review_tag_id as review_t3_11_1_ from review_review_tag reviewrevi0_ where reviewrevi0_.review_id=5;
Hibernate: 
    select
        reviewtag0_.review_tag_id as review_t1_12_0_,
        reviewtag0_.name as name2_12_0_ 
    from
        review_tag reviewtag0_ 
    where
        reviewtag0_.review_tag_id=?
2024-02-11 18:31:29.650  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889650 | took 6ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id=?
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id=4;
Hibernate: 
    select
        reviewtag0_.review_tag_id as review_t1_12_0_,
        reviewtag0_.name as name2_12_0_ 
    from
        review_tag reviewtag0_ 
    where
        reviewtag0_.review_tag_id=?
2024-02-11 18:31:29.666  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889666 | took 15ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id=?
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id=5;
Hibernate: 
    select
        program0_.program_id as program_1_7_0_,
        program0_.average_rating as average_2_7_0_,
        program0_.created_year as created_3_7_0_,
        program0_.poster_path as poster_p4_7_0_,
        program0_.review_count as review_c5_7_0_,
        program0_.title as title6_7_0_,
        program0_.tm_db_program_id as tm_db_pr7_7_0_,
        program0_.type as type8_7_0_ 
    from
        program program0_ 
    where
        program0_.program_id=?
2024-02-11 18:31:29.690  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889690 | took 22ms | statement | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select program0_.program_id as program_1_7_0_, program0_.average_rating as average_2_7_0_, program0_.created_year as created_3_7_0_, program0_.poster_path as poster_p4_7_0_, program0_.review_count as review_c5_7_0_, program0_.title as title6_7_0_, program0_.tm_db_program_id as tm_db_pr7_7_0_, program0_.type as type8_7_0_ from program program0_ where program0_.program_id=?
select program0_.program_id as program_1_7_0_, program0_.average_rating as average_2_7_0_, program0_.created_year as created_3_7_0_, program0_.poster_path as poster_p4_7_0_, program0_.review_count as review_c5_7_0_, program0_.title as title6_7_0_, program0_.tm_db_program_id as tm_db_pr7_7_0_, program0_.type as type8_7_0_ from program program0_ where program0_.program_id=3;
2024-02-11 18:31:29.698  INFO 29300 --- [nio-8080-exec-1] p6spy                                    : #1707643889698 | took 7ms | commit | connection 4| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB

;

총 2개의 리뷰를 조회하는데 실행되는 쿼리문의 수는 총 9개다.

 

엔티티 연관관계

리뷰 엔티티의 연관관계는 다음과 같다.

• 리뷰와 유저
  다대일 단방향 관계다.
• 리뷰와 프로그램
  다대일 단방향 관계다.
• 리뷰와 리뷰태그
  일대다 양방향 관계다. 리뷰리뷰태그라는 중간 테이블이 존재한다.

 

성능 최적화

페이징을 성능 최적화하는 방법은 다음과 같다.

1. xToOne 관계를 모두 Fetch Join한다.
2. 컬렉션은 지연 로딩으로 조회하고, 지연 로딩 성능 최적화를 위해 BatchSize를 적용한다.
   • hibernate.default_batch_fetch_size: 글로벌 설정
   • @BatchSize: 개별 최적화

 

1. xToOne 관계 Fetch Join

유저와 프로그램에 대해 Fetch Join을 적용할 수 있다.

하지만 스프링 데이터 JPA에서 @Query 어노테이션을 통해 fetch join할 때 하나의 엔티티만 지정할 수 있는듯하다. 따라서 여기서는 프로그램에 대해서만 페치조인을 수행한다.

QueryDsl이나 JDBC를 이용하면 두 엔티티에 대해 페치조인이 가능할 듯 싶다.

@Query("select r from Review r join fetch r.program where r.user.id =:userId")
Slice<Review> findByUserIdOrderByCreatedAt(Long userId, Pageable pageable);

 

2. BatchSize 적용

spring:
  jpa:
    open-in-view: true
    hibernate:
      ddl-auto: validate
    show-sql: true
    properties:
      hibernate.format_sql: true
      dialect: org.hibernate.dialect.MySQL8InnoDBDialect
      hibernate:
        default_batch_fetch_size: 10

application.yml 파일을 통해 글로벌로 batch size를 설정한다.

 

최적화 결과

2024-02-11 18:10:04.035  INFO 28784 --- [nio-8080-exec-5] t.OTTify.oauth.jwt.JwtAuthFilter         : checkAccessTokenAndAuthentication() 호출
2024-02-11 18:10:04.036  INFO 28784 --- [nio-8080-exec-5] tavebalak.OTTify.oauth.jwt.JwtService    : extractAccessToken() 호출
Hibernate: 
    select
        review0_.review_id as review_i1_10_0_,
        program1_.program_id as program_1_7_1_,
        review0_.created_at as created_2_10_0_,
        review0_.updated_at as updated_3_10_0_,
        review0_.content as content4_10_0_,
        review0_.genre as genre5_10_0_,
        review0_.like_counts as like_cou6_10_0_,
        review0_.program_id as program_8_10_0_,
        review0_.rating as rating7_10_0_,
        review0_.user_id as user_id9_10_0_,
        program1_.average_rating as average_2_7_1_,
        program1_.created_year as created_3_7_1_,
        program1_.poster_path as poster_p4_7_1_,
        program1_.review_count as review_c5_7_1_,
        program1_.title as title6_7_1_,
        program1_.tm_db_program_id as tm_db_pr7_7_1_,
        program1_.type as type8_7_1_ 
    from
        review review0_ 
    inner join
        program program1_ 
            on review0_.program_id=program1_.program_id 
    where
        review0_.user_id=? 
    order by
        review0_.created_at asc limit ?
2024-02-11 18:10:04.104  INFO 28784 --- [nio-8080-exec-5] p6spy                                    : #1707642604103 | took 9ms | statement | connection 5| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select review0_.review_id as review_i1_10_0_, program1_.program_id as program_1_7_1_, review0_.created_at as created_2_10_0_, review0_.updated_at as updated_3_10_0_, review0_.content as content4_10_0_, review0_.genre as genre5_10_0_, review0_.like_counts as like_cou6_10_0_, review0_.program_id as program_8_10_0_, review0_.rating as rating7_10_0_, review0_.user_id as user_id9_10_0_, program1_.average_rating as average_2_7_1_, program1_.created_year as created_3_7_1_, program1_.poster_path as poster_p4_7_1_, program1_.review_count as review_c5_7_1_, program1_.title as title6_7_1_, program1_.tm_db_program_id as tm_db_pr7_7_1_, program1_.type as type8_7_1_ from review review0_ inner join program program1_ on review0_.program_id=program1_.program_id where review0_.user_id=? order by review0_.created_at asc limit ?
select review0_.review_id as review_i1_10_0_, program1_.program_id as program_1_7_1_, review0_.created_at as created_2_10_0_, review0_.updated_at as updated_3_10_0_, review0_.content as content4_10_0_, review0_.genre as genre5_10_0_, review0_.like_counts as like_cou6_10_0_, review0_.program_id as program_8_10_0_, review0_.rating as rating7_10_0_, review0_.user_id as user_id9_10_0_, program1_.average_rating as average_2_7_1_, program1_.created_year as created_3_7_1_, program1_.poster_path as poster_p4_7_1_, program1_.review_count as review_c5_7_1_, program1_.title as title6_7_1_, program1_.tm_db_program_id as tm_db_pr7_7_1_, program1_.type as type8_7_1_ from review review0_ inner join program program1_ on review0_.program_id=program1_.program_id where review0_.user_id=1 order by review0_.created_at asc limit 11;
Hibernate: 
    select
        reviewrevi0_.review_id as review_i2_11_1_,
        reviewrevi0_.review_review_tag_id as review_r1_11_1_,
        reviewrevi0_.review_review_tag_id as review_r1_11_0_,
        reviewrevi0_.review_id as review_i2_11_0_,
        reviewrevi0_.review_tag_id as review_t3_11_0_ 
    from
        review_review_tag reviewrevi0_ 
    where
        reviewrevi0_.review_id in (
            ?, ?
        )
2024-02-11 18:10:04.115  INFO 28784 --- [nio-8080-exec-5] p6spy                                    : #1707642604115 | took 6ms | statement | connection 5| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewrevi0_.review_id as review_i2_11_1_, reviewrevi0_.review_review_tag_id as review_r1_11_1_, reviewrevi0_.review_review_tag_id as review_r1_11_0_, reviewrevi0_.review_id as review_i2_11_0_, reviewrevi0_.review_tag_id as review_t3_11_0_ from review_review_tag reviewrevi0_ where reviewrevi0_.review_id in (?, ?)
select reviewrevi0_.review_id as review_i2_11_1_, reviewrevi0_.review_review_tag_id as review_r1_11_1_, reviewrevi0_.review_review_tag_id as review_r1_11_0_, reviewrevi0_.review_id as review_i2_11_0_, reviewrevi0_.review_tag_id as review_t3_11_0_ from review_review_tag reviewrevi0_ where reviewrevi0_.review_id in (4, 5);
Hibernate: 
    select
        reviewtag0_.review_tag_id as review_t1_12_0_,
        reviewtag0_.name as name2_12_0_ 
    from
        review_tag reviewtag0_ 
    where
        reviewtag0_.review_tag_id in (
            ?, ?, ?
        )
2024-02-11 18:10:04.124  INFO 28784 --- [nio-8080-exec-5] p6spy                                    : #1707642604124 | took 9ms | statement | connection 5| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id in (?, ?, ?)
select reviewtag0_.review_tag_id as review_t1_12_0_, reviewtag0_.name as name2_12_0_ from review_tag reviewtag0_ where reviewtag0_.review_tag_id in (3, 4, 5);
Hibernate: 
    select
        user0_.user_id as user_id1_14_0_,
        user0_.created_at as created_2_14_0_,
        user0_.updated_at as updated_3_14_0_,
        user0_.average_rating as average_4_14_0_,
        user0_.code as code5_14_0_,
        user0_.email as email6_14_0_,
        user0_.grade as grade7_14_0_,
        user0_.nick_name as nick_nam8_14_0_,
        user0_.profile_photo as profile_9_14_0_,
        user0_.role as role10_14_0_,
        user0_.social_type as social_11_14_0_,
        user0_.review_counts as review_12_14_0_ 
    from
        `user` user0_ 
    where
        user0_.user_id=?
2024-02-11 18:10:04.131  INFO 28784 --- [nio-8080-exec-5] p6spy                                    : #1707642604131 | took 5ms | statement | connection 5| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB
select user0_.user_id as user_id1_14_0_, user0_.created_at as created_2_14_0_, user0_.updated_at as updated_3_14_0_, user0_.average_rating as average_4_14_0_, user0_.code as code5_14_0_, user0_.email as email6_14_0_, user0_.grade as grade7_14_0_, user0_.nick_name as nick_nam8_14_0_, user0_.profile_photo as profile_9_14_0_, user0_.role as role10_14_0_, user0_.social_type as social_11_14_0_, user0_.review_counts as review_12_14_0_ from `user` user0_ where user0_.user_id=?
select user0_.user_id as user_id1_14_0_, user0_.created_at as created_2_14_0_, user0_.updated_at as updated_3_14_0_, user0_.average_rating as average_4_14_0_, user0_.code as code5_14_0_, user0_.email as email6_14_0_, user0_.grade as grade7_14_0_, user0_.nick_name as nick_nam8_14_0_, user0_.profile_photo as profile_9_14_0_, user0_.role as role10_14_0_, user0_.social_type as social_11_14_0_, user0_.review_counts as review_12_14_0_ from `user` user0_ where user0_.user_id=1;
2024-02-11 18:10:04.140  INFO 28784 --- [nio-8080-exec-5] p6spy                                    : #1707642604140 | took 8ms | commit | connection 5| url jdbc:mysql://proddb-mysql.c1y4skgea7wb.ap-northeast-2.rds.amazonaws.com:3306/OTTifyDB

;

페이징 처리 성능 최적화를 통해 실행되는 쿼리의 개수가 9개에서 4개로 줄어든 것을 확인할 수 있다.