Changes between Version 20 and Version 21 of P5

Timestamp:

04/21/26 12:01:28 (11 days ago)

Author:

211099

Comment:

--

P5

@@ -139 +139 @@
 NEED_APPROVAL(suggestion_id, story_id, chapter_id) → There are no other attributes, so it satisfies 2NF.
 
+For a decomposition to be lossless, the common attributes between two joined relations must be a superkey in at least one of them. We verify this for all connected relations:
+
+CHAPTER ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+STORY ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+READING_LIST ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+AI_SUGGESTION ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+COMMENT ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+COMMENT ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+STATUS ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+CONTENT_TYPE ⋈ NOTIFICATION: common attribute notification_id → notification_id is the primary key of NOTIFICATION 
+
+SUGGESTION_TYPE ⋈ AI_SUGGESTION: common attribute suggestion_id → suggestion_id is the primary key of AI_SUGGESTION 
+
+LIKES ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+LIKES ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+COLLABORATION ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+COLLABORATION ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+ROLES ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+ROLES ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+PERMISSION_LEVEL ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+PERMISSION_LEVEL ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+HAS_GENRE ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+HAS_GENRE ⋈ GENRE: common attribute genre_id → genre_id is the primary key of GENRE 
+
+READING_LIST_ITEMS ⋈ READING_LIST: common attribute list_id → list_id is the primary key of READING_LIST 
+
+READING_LIST_ITEMS ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+NOTIFY ⋈ USERS: common attribute user_id → user_id is the primary key of USERS 
+
+NOTIFY ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+NOTIFY ⋈ NOTIFICATION: common attribute notification_id → notification_id is the primary key of NOTIFICATION 
+
+NEED_APPROVAL ⋈ AI_SUGGESTION: common attribute suggestion_id → suggestion_id is the primary key of AI_SUGGESTION 
+
+NEED_APPROVAL ⋈ STORY: common attribute story_id → story_id is the primary key of STORY 
+
+NEED_APPROVAL ⋈ CHAPTER: common attribute chapter_id → chapter_id is the primary key of CHAPTER 
+
+In every case the common attributes form a primary key in at least one of the joined relations, so all joins are lossless and no information is lost during decomposition.
+
 Since there are no partial dependencies in any of the resulting tables, this schema satisfies 2NF.