Chapter 6: Normalization

What is first normal form (1NF)?

1NF or first normal form is the first stage in the normalization process. It describes a relation depicted in tabular format, with no repeating groups and a primary key identified. All nonkey attributes in the relation are dependent on the primary key.

What is key attributes?

Key attributes are the sttributes that form a primary key...See also prime attribute.

What is second normal form (2NF)?

2NF or second normal form is the second stage in the normalization process, in which a relation is in 1NF and there are no partial dependencies-(dependencies in only part of the primary key).

What is third normal form (3NF)?

3NF or third normal form is a table in 2NF where no nonkey attribute is functionally dependent on another nonkey attribute; that is, it cannot include transitive dependencis.

What is fourth normal form (4NF)?

4NF or fourth normal form is a table that contains no multiple independent sets of multivalued dependencies.

What is atomic attribute?

Atomic attribute is an attribute that cannot be further subdivided to produce meaningful components. For example, a person's last name attribute cannot be meaningfully subdivided/

What is atomicity?

Atomicity is not being able to be divided into smaller units.

What is Boyce-Codd normal form (BCNF)?

BCNF or Boyce-Codd normal form is a special type of third normal form or 3NF in which every determinant is a candidate key. A table in BCNF must be in 3NF...See also determinant.

What is denormalization?

Denormalization is a process by which a table is changed from a higher-level normal form to a lower-level normal form, usually ro increase processing speed. Denormalization potentially yields data anomalies.

What is dependency diagram?

Dependecy diagram is a representation of all data dependencies (primary key, partial & transitive dependencies) within a table.

What is determinant?

Determinant is any attribute in a specific row whose value directly determines other values in that row.

What is granularity?

Granularity is the level of detail represented by the values stored in a table's row. Data stored at its lowest level of granularity is said to be atomic data.

What is nonkey attribute?

Nonkey attribute is an attribute that is not part of a key.

What is nonprime attribute?

Nonprime attribute is an attribute that is not part of a key.

What is normalization?

Normalization is a process that assigns attributes to entities so that data redundancies are reduced or eliminated.

What is partial dependency?

Partial dependecy is a condition in which an attribute is dependent on only a portion/subset of the primary key.

What is prime attribute?

Prime attribute is a key attribute; that is, an attribute that is part of a key or is the whole key...See also key attributes.

What is repeating group?

Repeating group is, in a relation, a characteristic describing a group of multiple entries of the same type for a single key attribute occurrence. For example, a car can have multiple colors for its top, interior, bottom, trim, and so on.

What is transitive dependency?

Transitive dependecy is a condition in which an attribute is dependent on another attribute that is not part of the primary key.