diff --git a/book/300_architecture/database/tables.md b/book/300_architecture/database/tables.md
index b41d457..91b8afd 100644
--- a/book/300_architecture/database/tables.md
+++ b/book/300_architecture/database/tables.md
@@ -1,7 +1,7 @@
 # PostgreSQL 테이블 구조
 
 ## 작성일: 2025-08-20
-## 최종 수정일: 2025-09-24
+## 최종 수정일: 2025-12-04
 ## 데이터베이스: main_db
 
 ---
@@ -34,14 +34,36 @@
 | email | VARCHAR(255) | NO | UNIQUE |
 | name | VARCHAR(255) | YES | |
 | picture | VARCHAR(500) | YES | |
-| oauth_provider | VARCHAR(50) | YES | google/slack |
-| oauth_id | VARCHAR(255) | YES | |
+| oauth_providers | JSONB | YES | OAuth 정보 (google/slack/naverworks) |
 | is_active | BOOLEAN | YES | |
 | last_login_at | TIMESTAMPTZ | YES | |
 | created_at | TIMESTAMPTZ | YES | |
 | updated_at | TIMESTAMPTZ | YES | |
 | username | VARCHAR(64) | YES | |
 | is_admin | BOOLEAN | NO | |
+| metadata | JSONB | YES | 사용자 확장 정보 (nickname, position, preferences 등) |
+
+**metadata 예시**:
+```json
+{
+  "nickname": "joann",
+  "position": "CEO",
+  "department": "경영",
+  "preferences": {
+    "communication": "direct",
+    "work_style": "flexible"
+  }
+}
+```
+
+**oauth_providers 예시**:
+```json
+{
+  "google": "oauth_id_123",
+  "slack": "U01234567",
+  "naverworks": "nw_user_id"
+}
+```
 
 ### workspace_member
 | 컬럼명 | 타입 | NULL | 설명 |