=== 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 || V02 || Garden Venue || Outdoor || 200 || B02 || 2026-06-12 || 12:00 || 16:00 |
|| U02 || Marko || Iliev || marko@mail.com
 || W02 || 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**