refactor(backend): 순차 쿼리 → 병렬 처리

- getAlbumDetails: tracks/teasers/photos 쿼리 Promise.all로 병렬 실행
- photos.js: 멤버 INSERT for loop → VALUES 배치 처리

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/routes/albums/photos.js

@@ -166,12 +166,11 @@ export default async function photosRoutes(fastify) {
           photoId = result.insertId;
 
           if (meta.members && meta.members.length > 0) {
-            for (const memberId of meta.members) {
-              await connection.query(
-                'INSERT INTO album_photo_members (photo_id, member_id) VALUES (?, ?)',
-                [photoId, memberId]
-              );
-            }
+            const values = meta.members.map(memberId => [photoId, memberId]);
+            await connection.query(
+              'INSERT INTO album_photo_members (photo_id, member_id) VALUES ?',
+              [values]
+            );
           }
         }
 

backend/src/services/album.js

@@ -10,33 +10,35 @@
  * @returns {object} 상세 정보가 포함된 앨범
  */
 export async function getAlbumDetails(db, album) {
-  const [tracks] = await db.query(
-    'SELECT * FROM album_tracks WHERE album_id = ? ORDER BY track_number',
-    [album.id]
-  );
+  // 트랙, 티저, 포토 병렬 조회
+  const [[tracks], [teasers], [photos]] = await Promise.all([
+    db.query(
+      'SELECT * FROM album_tracks WHERE album_id = ? ORDER BY track_number',
+      [album.id]
+    ),
+    db.query(
+      `SELECT original_url, medium_url, thumb_url, video_url, media_type
+       FROM album_teasers WHERE album_id = ? ORDER BY sort_order`,
+      [album.id]
+    ),
+    db.query(
+      `SELECT
+        p.id, p.original_url, p.medium_url, p.thumb_url, p.photo_type, p.concept_name, p.sort_order,
+        p.width, p.height,
+        GROUP_CONCAT(m.name ORDER BY m.id SEPARATOR ', ') as members
+      FROM album_photos p
+      LEFT JOIN album_photo_members pm ON p.id = pm.photo_id
+      LEFT JOIN members m ON pm.member_id = m.id
+      WHERE p.album_id = ?
+      GROUP BY p.id
+      ORDER BY p.sort_order`,
+      [album.id]
+    ),
+  ]);
+
   album.tracks = tracks;
-
-  const [teasers] = await db.query(
-    `SELECT original_url, medium_url, thumb_url, video_url, media_type
-     FROM album_teasers WHERE album_id = ? ORDER BY sort_order`,
-    [album.id]
-  );
   album.teasers = teasers;
 
-  const [photos] = await db.query(
-    `SELECT
-      p.id, p.original_url, p.medium_url, p.thumb_url, p.photo_type, p.concept_name, p.sort_order,
-      p.width, p.height,
-      GROUP_CONCAT(m.name ORDER BY m.id SEPARATOR ', ') as members
-    FROM album_photos p
-    LEFT JOIN album_photo_members pm ON p.id = pm.photo_id
-    LEFT JOIN members m ON pm.member_id = m.id
-    WHERE p.album_id = ?
-    GROUP BY p.id
-    ORDER BY p.sort_order`,
-    [album.id]
-  );
-
   const conceptPhotos = {};
   for (const photo of photos) {
     const concept = photo.concept_name || 'Default';

docs/refactoring.md

@@ -60,9 +60,13 @@
 
 ---
 
-### 7단계: 순차 쿼리 → 병렬 처리
-- [ ] `services/album.js` getAlbumDetails - tracks, teasers, photos 병렬 조회
-- [ ] `routes/albums/photos.js` - 멤버 INSERT 배치 처리
+### 7단계: 순차 쿼리 → 병렬 처리 ✅ 완료
+- [x] `services/album.js` getAlbumDetails - tracks, teasers, photos 병렬 조회
+- [x] `routes/albums/photos.js` - 멤버 INSERT 배치 처리
+
+**수정된 파일:**
+- `src/services/album.js` - Promise.all로 3개 쿼리 병렬 실행
+- `src/routes/albums/photos.js` - for loop → VALUES ? 배치 INSERT
 
 ---
 
@@ -107,7 +111,7 @@
 | 4단계 | 에러 처리 통일 | ✅ 완료 |
 | 5단계 | 중복 코드 제거 | ✅ 완료 |
 | 6단계 | 매직 넘버 config 이동 | ✅ 완료 |
-| 7단계 | 순차→병렬 쿼리 | 대기 |
+| 7단계 | 순차→병렬 쿼리 | ✅ 완료 |
 | 8단계 | meilisearch 카테고리 ID | 대기 |
 | 9단계 | 응답 형식 통일 | 대기 |
 | 10단계 | 로거 통일 | 대기 |