[Refactor] 스터디 필터링 조회 성능 향상을 위한 통계성 데이터 비정규화 및 쿼리 개선

modules/study/src/main/java/kr/spot/study/application/command/CreateStudyService.java

@@ -6,14 +6,12 @@
 import kr.spot.study.domain.associations.StudyCategory;
 import kr.spot.study.domain.associations.StudyMember;
 import kr.spot.study.domain.associations.StudyRegion;
-import kr.spot.study.domain.associations.StudyStats;
 import kr.spot.study.domain.associations.StudyStyle;
 import kr.spot.study.domain.vo.Fee;
 import kr.spot.study.infrastructure.jpa.StudyRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyCategoryRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyMemberRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyRegionRepository;
-import kr.spot.study.infrastructure.jpa.associations.StudyStatsRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyStyleRepository;
 import kr.spot.study.presentation.command.dto.request.CreateStudyRequest;
 import lombok.RequiredArgsConstructor;
@@ -34,18 +32,15 @@ public class CreateStudyService {
   private final StudyStyleRepository studyStyleRepository;
   private final StudyRegionRepository studyRegionRepository;
   private final StudyCategoryRepository studyCategoryRepository;
-  private final StudyStatsRepository studyStatsRepository;
   private final StudyMemberRepository studyMemberRepository;
 
   public long createStudy(CreateStudyRequest request, long leaderId, MultipartFile imageFile) {
     long studyId = idGenerator.nextId();
     Study study = Study.of(studyId, leaderId, request.name(), request.maxMembers(),
         Fee.of(request.hasFee(), request.amount()), null, request.description(), request.isOnline());
-    StudyStats studyStats = StudyStats.of(studyId);
     StudyMember studyMember = StudyMember.create(idGenerator.nextId(), studyId, leaderId);
 
     studyRepository.save(study);
-    studyStatsRepository.save(studyStats);
     studyMemberRepository.save(studyMember);
 
     saveAllStudyCategories(request, studyId);

modules/study/src/main/java/kr/spot/study/application/command/StudyLikeService.java

@@ -1,8 +1,8 @@
 package kr.spot.study.application.command;
 
 import kr.spot.IdGenerator;
+import kr.spot.study.infrastructure.jpa.StudyRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyLikeRepository;
-import kr.spot.study.infrastructure.jpa.associations.StudyStatsRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -14,7 +14,7 @@ public class StudyLikeService {
 
   private final IdGenerator idGenerator;
   private final StudyLikeRepository studyLikeRepository;
-  private final StudyStatsRepository studyStatsRepository;
+  private final StudyRepository studyRepository;
 
   public void likeStudy(long studyId, long memberId) {
     int inserted = studyLikeRepository.saveStudyLike(idGenerator.nextId(), studyId, memberId);
@@ -23,14 +23,14 @@ public void likeStudy(long studyId, long memberId) {
 
   private void increaseLikeCount(long studyId, int inserted) {
     if (inserted == 1) {
-      studyStatsRepository.increaseLike(studyId);
+      studyRepository.increaseLike(studyId);
     }
   }
 
   public void unlikeStudy(long studyId, long memberId) {
     int deleted = studyLikeRepository.hardDelete(studyId, memberId);
     if (deleted > 0) {
-      studyStatsRepository.decreaseLike(studyId);
+      studyRepository.decreaseLike(studyId);
     }
   }
 }

modules/study/src/main/java/kr/spot/study/application/query/GetStudyDetailService.java

@@ -7,13 +7,11 @@
 import kr.spot.study.domain.Study;
 import kr.spot.study.domain.associations.StudyCategory;
 import kr.spot.study.domain.associations.StudyMember;
-import kr.spot.study.domain.associations.StudyStats;
 import kr.spot.study.domain.enums.Category;
 import kr.spot.study.domain.enums.StudyMemberStatus;
 import kr.spot.study.infrastructure.jpa.StudyRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyCategoryRepository;
 import kr.spot.study.infrastructure.jpa.associations.StudyMemberRepository;
-import kr.spot.study.infrastructure.jpa.associations.StudyStatsRepository;
 import kr.spot.study.presentation.query.dto.response.GetStudyInfoResponse;
 import kr.spot.study.presentation.query.dto.response.GetStudyInfoResponse.Statistics;
 import kr.spot.study.presentation.query.dto.response.GetStudyMembersResponse;
@@ -32,16 +30,14 @@ public class GetStudyDetailService {
 
   private final StudyRepository studyRepository;
   private final StudyCategoryRepository studyCategoryRepository;
-  private final StudyStatsRepository studyStatsRepository;
   private final StudyMemberRepository studyMemberRepository;
   private final StudyViewCountService studyViewCountService;
   private final GetMemberInfoPort getMemberInfoPort;
 
   public GetStudyInfoResponse getStudyInfo(long studyId, long viewerId) {
     Study study = findStudy(studyId);
-    StudyStats stats = findStudyStats(studyId);
     List<Category> categories = findCategories(studyId);
-    Statistics statistics = buildStatistics(study, stats, studyId, viewerId);
+    Statistics statistics = buildStatistics(study, studyId, viewerId);
 
     return toStudyInfoResponse(study, categories, statistics);
   }
@@ -58,23 +54,19 @@ private Study findStudy(long studyId) {
     return studyRepository.getStudyById(studyId);
   }
 
-  private StudyStats findStudyStats(long studyId) {
-    return studyStatsRepository.getByStudyId(studyId);
-  }
-
   private List<Category> findCategories(long studyId) {
     return studyCategoryRepository.findAllByStudyId(studyId).stream()
         .map(StudyCategory::getCategory)
         .toList();
   }
 
-  private Statistics buildStatistics(Study study, StudyStats stats, long studyId, long viewerId) {
-    long displayViewCount = studyViewCountService.calculateDisplayViewCount(stats, studyId,
+  private Statistics buildStatistics(Study study, long studyId, long viewerId) {
+    long displayViewCount = studyViewCountService.calculateDisplayViewCount(study, studyId,
         viewerId);
     return Statistics.of(
         study.getMaxMembers(),
         study.getCurrentMembers(),
-        stats.getLikeCount(),
+        study.getLikeCount(),
         displayViewCount
     );
   }

modules/study/src/main/java/kr/spot/study/application/query/StudyViewCountService.java

@@ -1,6 +1,6 @@
 package kr.spot.study.application.query;
 
-import kr.spot.study.domain.associations.StudyStats;
+import kr.spot.study.domain.Study;
 import kr.spot.view.ViewAbuseGuard;
 import kr.spot.view.ViewCounter;
 import kr.spot.view.ViewableType;
@@ -16,8 +16,8 @@ public class StudyViewCountService {
   private final ViewCounter viewCounter;
   private final ViewAbuseGuard viewAbuseGuard;
 
-  public long calculateDisplayViewCount(StudyStats stats, long studyId, long viewerId) {
-    long baseViewCount = stats.getViewCount();
+  public long calculateDisplayViewCount(Study study, long studyId, long viewerId) {
+    long baseViewCount = study.getViewCount();
     long viewDelta = getViewDeltaFromCounter(studyId, viewerId);
     return baseViewCount + viewDelta;
   }

modules/study/src/main/java/kr/spot/study/domain/Study.java

@@ -60,6 +60,10 @@ public class Study extends BaseEntity {
   @Column(nullable = false)
   private Boolean isOnline = false;
 
+  private Long viewCount;
+
+  private Long likeCount;
+
   public static Study of(Long id, Long leaderId, String name, Integer maxMembers, Fee fee,
       String description) {
     return of(id, leaderId, name, maxMembers, fee, null, description, false);
@@ -75,7 +79,7 @@ public static Study of(Long id, Long leaderId, String name, Integer maxMembers,
     validateStudyNameIsNotBlank(name);
     validateMaxMembers(maxMembers);
     return new Study(id, leaderId, name, maxMembers, CURRENT_MEMBERS, fee, imageUrl, description,
-        RecruitingStatus.RECRUITING, isOnline != null && isOnline);
+        RecruitingStatus.RECRUITING, isOnline != null && isOnline, 0L, 0L);
   }
 
   private static void validateStudyNameIsNotBlank(String name) {

modules/study/src/main/java/kr/spot/study/infrastructure/batch/StudyViewFlusher.java

@@ -1,6 +1,6 @@
 package kr.spot.study.infrastructure.batch;
 
-import kr.spot.study.infrastructure.jpa.associations.StudyStatsRepository;
+import kr.spot.study.infrastructure.jpa.StudyRepository;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
@@ -12,11 +12,11 @@
 @RequiredArgsConstructor
 public class StudyViewFlusher {
 
-  private final StudyStatsRepository studyStatsRepository;
+  private final StudyRepository studyRepository;
 
   @Transactional(propagation = Propagation.REQUIRES_NEW)
   public void updateViewCount(long studyId, long delta) {
-    studyStatsRepository.increaseViewBy(studyId, delta);
+    studyRepository.increaseViewBy(studyId, delta);
     log.debug("스터디 조회수 DB 업데이트: studyId={}, delta={}", studyId, delta);
   }
 }

modules/study/src/main/java/kr/spot/study/infrastructure/jpa/StudyRepository.java

@@ -5,6 +5,9 @@
 import kr.spot.study.domain.Study;
 import kr.spot.study.domain.enums.RecruitingStatus;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 public interface StudyRepository extends JpaRepository<Study, Long> {
 
@@ -16,4 +19,21 @@ default Study getStudyById(Long studyId) {
   long countByLeaderIdAndRecruitingStatus(long leaderId, RecruitingStatus recruitingStatus);
 
   boolean existsByLeaderId(long leaderId);
+
+  @Modifying
+  @Query("""
+      update Study s
+         set s.viewCount = s.viewCount + :delta,
+             s.updatedAt = CURRENT_TIMESTAMP
+       where s.id = :studyId
+      """)
+  int increaseViewBy(@Param("studyId") long studyId, @Param("delta") long delta);
+
+  @Modifying
+  @Query("update Study s set s.likeCount = s.likeCount + 1 where s.id = :studyId")
+  int increaseLike(@Param("studyId") long studyId);
+
+  @Modifying
+  @Query("update Study s set s.likeCount = case when s.likeCount > 0 then s.likeCount - 1 else 0 end where s.id = :studyId")
+  int decreaseLike(@Param("studyId") long studyId);
 }