Merge pull request #153 from team-gogo/update/rank-query-covering-index

[stage] 랭킹 조회 쿼리 커버링 인덱스 적용

Author: vumrra

src/main/kotlin/gogo/gogostage/domain/stage/root/application/dto/StageDto.kt

@@ -170,6 +170,12 @@ data class QueryMyStageInfoDto(
     val isMaintaining: Boolean
 )
 
+data class StageParticipantPointOnly(
+    val id: Long,
+    val studentId: Long,
+    val point: Long
+)
+
 data class StageParticipantPointRankDto(
     val info: PageDto,
     val rank: List<PointRankDto>

src/main/kotlin/gogo/gogostage/domain/stage/root/persistence/StageCustomRepositoryImpl.kt

@@ -1,10 +1,12 @@
 package gogo.gogostage.domain.stage.root.persistence
 
 import com.querydsl.core.BooleanBuilder
+import com.querydsl.core.types.Projections
 import com.querydsl.jpa.impl.JPAQueryFactory
 import gogo.gogostage.domain.stage.participant.root.persistence.QStageParticipant.stageParticipant
 import gogo.gogostage.domain.stage.root.application.dto.PageDto
 import gogo.gogostage.domain.stage.root.application.dto.PointRankDto
+import gogo.gogostage.domain.stage.root.application.dto.StageParticipantPointOnly
 import gogo.gogostage.domain.stage.root.application.dto.StageParticipantPointRankDto
 import gogo.gogostage.global.internal.student.api.StudentApi
 import org.springframework.data.domain.Pageable
@@ -21,7 +23,16 @@ class StageCustomRepositoryImpl(
 
         predicate.and(stageParticipant.stage.id.eq(stage.id))
 
-        val studentParticipants = queryFactory.selectFrom(stageParticipant)
+        val studentParticipants = queryFactory
+            .select(
+                Projections.constructor(
+                    StageParticipantPointOnly::class.java,
+                    stageParticipant.id,
+                    stageParticipant.studentId,
+                    stageParticipant.point
+                )
+            )
+            .from(stageParticipant)
             .where(predicate)
             .orderBy(stageParticipant.point.desc())
             .offset(pageable.offset)
@@ -59,4 +70,4 @@ class StageCustomRepositoryImpl(
 
     }
 
-}
+}