How do functional dependencies affect normalization?

How do functional dependencies affect normalization?

A full functional dependency is a state of database normalization that equates to the normalization standard of Second Normal Form (2NF). In brief, this means that it meets the requirements of First Normal Form (1NF), and all non-key attributes are fully functionally dependent on the primary key.

What is functional dependency in normalization?

Functional dependency (FD) is a set of constraints between two attributes in a relation. Functional dependency is represented by an arrow sign (→) that is, X→Y, where X functionally determines Y. The left-hand side attributes determine the values of attributes on the right-hand side.

How do you find the minimal cover of a functional dependency?

Here, EI → C is redundant (C can be determined using other FD, in this case, A → C). Hence, the minimal cover Fc = {A → C, C → D, C → I, EC → A, EC → B}. Hence, set of functional dependencies Fc is the minimal cover for the set F.

What is the minimal normal form that a relation must satisfy?

First normal form (1NF) is the minimal normal form that a relation must satisfy. First normal form (1NF) states that values of an attribute or column must be atomic. That is, at the intersection of each and every column there should be one and only single value.

What is meant by functional dependency?

A functional dependency (FD) is a relationship between two attributes, typically between the PK and other non-key attributes within a table. For any relation R, attribute Y is functionally dependent on attribute X (usually the PK), if for every valid instance of X, that value of X uniquely determines the value of Y.

What is a functional dependency with example?

In functional dependency we can obtain the value of another attribute from given attribute. For example, If we know the value of student roll number, we can obtain student address, marks etc. By this, we say that student address and marks is functionally dependent on student roll number.

What is minimal cover explain the properties of minimal cover?

A minimal cover is a simplified and reduced version of the given set of functional dependencies. Since it is a reduced version, it is also called as Irreducible set. It is also called as Canonical Cover. 1) Split the right-hand attributes of all FDs.

Is minimal cover same as canonical cover?

A canonical cover is “allowed” to have more than one attribute on the right hand side. A minimal cover cannot. As an example, the canonical cover may be “A -> BC” where the minimal cover would be “A -> B, A -> C”. That is the only difference.