This learning tool shows you how you can derive superkeys and candidate keys from functional dependencies. This is useful for when you want to determine the specific normal form of a relation.
How to use
Here's how to use the candidate key calculator:
- Specify the attributes in your relation.
- Enter the functional dependencies in your relation.
- Check that the tool parses your functional dependencies correctly.
- Review the calculated superkeys for your relation.
- Identify the candidate keys (minimal superkeys).
Relation attributes
Parsed attributes: {}
Functional Dependencies
Parsing Errors
Input format description
Enter each functional dependency on a separate line using single letters:
A -> B
Write multiple attributes without spaces:
AB -> CD
Example input
A -> B B -> C AC -> D CD -> EF
Parsed Dependencies
These are the determinants and dependents from your functional dependencies:
| α (Determinant) | β (Dependent) |
|---|
Superkeys
These are all sets of attributes that uniquely determine all other attributes in your relation:
| Superkey | Size |
|---|
Candidate keys
These are the minimal sets of attributes that uniquely determine all other
attributes in your relation. This implements the algorithm
find_candidate_keys(A, F) described in the
Candidate key Wikipedia article.
| Candidate Key |
|---|