FUNCTIONAL DEPENDENCY
Functional dependency is a fundamental concept in database management and
design, specifically within the context of relational databases. It describes a
relationship between attributes (or columns) in a relational table, indicating
how the values of one set of attributes determine or are related to the values
of another set of attributes. Functional dependency helps ensure data integrity
and plays a crucial role in the normalization process.
Here's a detailed explanation of functional dependency:
1. **Definition**:
- A functional dependency is a relationship between two sets of attributes:
the left-hand side (LHS) and the right-hand side (RHS).
- It is denoted as X -> Y, where X is a set of attributes (one or more) in a table,
and Y is a set of attributes (also one or more) in the same table.
- The functional dependency X -> Y means that, for any given set of values for
the attributes in X, there is only one possible set of values for the attributes in
Y.
2. **Examples**:
- In a table representing employees, if we have a functional dependency:
```
{EmployeeID} -> {EmployeeName, Department}
```
This means that for each unique EmployeeID, there is only one
corresponding EmployeeName and Department.
- Another example:
