Normal Form

1NF: All attributes domains
- Meaning each attribute is not nested/composite values
- domains can be strings/dates/numbers etc (NOT lists/sets)
2NF: 1NF holds. No Functional Dependency from any proper subset of a candidate key to a non-prime attribute
- Eg if candidate key was $A B$ , and $C$ and $D$ are not prime (not in any candidate keys)
  - $A \to C$ or $B \to D$ can't exist
3NF: 2NF holds. For every FD $X \to A$ either $X$ is a Superkey or $A$ is a prime attribute
- Synthesis Algorithm
BCNF: For every non-trival FD $X \to Y$ , $X$ is a Superkey
- BCNF Decomposition Algorithm

To apply

Compute all candidate keys via Attribute Closure
Identify prime vs non-prime attributes
Test each FD for partial (2NF), transitive (3NF) violations and key-status (BCNF)