=== Initial Unnormalized Relation (UNF) ===

The system initially stores all information in a single relation:

USER_WEDDING_VENUE(user_id, user_first_name, user_last_name, user_email, wedding_id, wedding_date, wedding_budget, venue_id, venue_name, venue_type, venue_capacity, booking_id, booking_date, start_time, end_time)

=== Example of UNF Data ===

|| user_id || user_first_name || user_last_name || user_email || wedding_id || wedding_date || wedding_budget || venue_id || venue_name || venue_type || venue_capacity || booking_id || booking_date || start_time || end_time 
|| U01 || Ana || Petrova || ana@mail.com|| W01 || 2026-06-12 || 15000 || V01 || Grand Hall || Ballroom || 300 || B01 || 2026-06-12 || 18:00 || 23:00 
|| U01 || Ana || Petrova || ana@mail.com|| W01 || 2026-06-12 || 15000 || V01 || Garden Venue || Outdoor || 200 || B02 || 2026-06-12 || 12:00 || 16:00 
|| U02 || Marko || Iliev || marko@mail.com|| W01 || 2026-09-20 || 20000 || V01 || Grand Hall || Ballroom || 300 || B03 || 2026-09-20 || 19:00 || 01:00 ||

=== Why This Relation Is UNF ===

**-Repeating groups exist:**


--User and wedding data are repeated for each venue booking

**-Redundancy:**


--Venue details (name, type, capacity) are duplicated across multiple rows
--User information appears multiple times

**-Update anomalies:
**

--Changing a venue name requires updating multiple rows
--Changing a user email risks inconsistent data

**-Insertion anomalies:**


--A venue cannot be stored unless it is booked
--A user cannot exist without a wedding

**-Deletion anomalies:**


--Deleting a booking may remove venue or wedding information

This relation contains attributes describing multiple entities (User, Wedding, Venue, Booking).
Storing all data together leads to redundancy and update anomalies.



**Identified Functional Dependencies (FDs):**

-user_id → user_first_name, user_last_name, user_email


-wedding_id → wedding_date, wedding_budget, user_id


-venue_id → venue_name, venue_type, venue_capacity


-booking_id → venue_id, wedding_id, booking_date, start_time, end_time

=== Step 1: Decomposition to 1NF (First Normal Form) ===

Definition of 1NF:

-A relation is in 1NF if all attributes contain atomic values


-No repeating groups or multivalued attributes exist


-Each row is uniquely identifiable by a key



The relation is decomposed based on entity responsibility while preserving all data.

=== R1: USER ===

|| Table || Attributes ||
|| R1 || user_id, user_first_name, user_last_name, user_email ||

Primary Key:
-user_id

Functional Dependency:
-user_id → user_first_name, user_last_name, user_email

**Justification:**


-All attributes are atomic


-All attributes depend only on user_id


-user_id uniquely identifies a system user


-No repeating groups exist

**Conclusion:
-R1 satisfies 1NF**

=== R2: WEDDING ===

|| Table || Attributes ||
|| R2 || wedding_id, wedding_date, wedding_budget, user_id ||

Primary Key:
-wedding_id

Foreign Key:
-user_id → USER(user_id)

Functional Dependency:
-wedding_id → wedding_date, wedding_budget, user_id

**Justification:**


-Each wedding is uniquely identified by wedding_id


-user_id represents ownership of the wedding


-All non-key attributes depend solely on wedding_id

**Conclusion:
-R2 satisfies 1NF
**
=== R3: VENUE ===

|| Table || Attributes ||
|| R3 || venue_id, venue_name, venue_type, venue_capacity ||

Primary Key:
-venue_id

Functional Dependency:
-venue_id → venue_name, venue_type, venue_capacity

**Justification:**


-Venue attributes describe a single independent entity


-Attributes are static and not dependent on other relations


-venue_id uniquely identifies a venue


**Conclusion:
-R3 satisfies 1NF**

=== R4: VENUE_BOOKING ===

|| Table || Attributes ||
|| R4 || booking_id, venue_id, wedding_id, booking_date, start_time, end_time ||

Primary Key:
-booking_id

Foreign Keys:
-venue_id → VENUE(venue_id)
-wedding_id → WEDDING(wedding_id)

Functional Dependency:
-booking_id → venue_id, wedding_id, booking_date, start_time, end_time


**Justification:**


-A booking represents a reservation of a venue for a specific wedding


-booking_id uniquely identifies each reservation


-All attributes depend directly on booking_id



**Conclusion:
-R4 satisfies 1NF**