Normalization Diagnostics

248 tables analyzed · NF level detection · 1NF–BCNF · Before/after schema simulation

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Overall NF Score

/ 100 · Average 2.6NF

Violations Found

Across 248 tables

Tables Below 3NF

9.3% of all tables

BCNF Compliant

189

76.2% of all tables

Normalization Forms Explained

1NF

Atomic values, no repeating groups. 3 tables fail — multi-value columns detected.

2NF

No partial dependencies. 6 tables fail — non-key columns depend on part of composite key.

3NF

No transitive dependencies. 14 tables fail — non-key columns depend on other non-key columns.

BCNF

Every determinant is a candidate key. 36 tables fail — stricter than 3NF.

4NF+

No multi-valued dependencies. 189 tables fully compliant with BCNF and above.

Per-Table Normalization Report

Table	NF Level	Violation Type	Affected Columns	Severity
order_tags	Fails 1NF	Multi-value column: `tags` stores comma-separated values	tags, category_tags	Critical
user_sessions	Fails 2NF	Partial dependency: `user_agent` depends on user_id only (not session)	user_agent, device_type	High
products	Fails 3NF	Transitive dependency: `category_name` → category_id → product_id	category_name, supplier_name	Medium
order_reports	Fails 2NF	Partial dependency on composite key (order_id, report_date)	customer_email, customer_name	High
employees	Fails 3NF	Transitive: `department_name` depends on dept_id, not employee_id	department_name, manager_name	Medium
customer_preferences	Fails 1NF	Repeating group: `pref_1, pref_2, pref_3` columns	pref_1 … pref_5	Critical

Before / After — products

Before (Violation)

After (Fix)

Migration Script

Problem: products stores category_name which creates a transitive dependency. If category name changes, every product row must be updated (update anomaly).

-- BEFORE: products table with 3NF violation CREATE TABLE products ( id INT PRIMARY KEY, name VARCHAR(200) NOT NULL, category_id INT NOT NULL, category_name VARCHAR(100), -- ⚠ Transitive dep: category_name → category_id supplier_name VARCHAR(200), -- ⚠ Transitive dep: supplier_name → supplier_id supplier_id INT, price DECIMAL(10,2), sku VARCHAR(50) UNIQUE );