02_06 Normalization of Database Tables Flashcards
An attribute that cannot be further subdivided to produce meaningful components
For example, a person’s last name attribute cannot be meaningfully subdivided
atomic (simple) attribute
The transaction property that requires all parts of a transaction to be treated as a single, indivisible, logical unit of work.
All parts of a transaction must be completed or the entire transaction is aborted.
atomicity
A special type of 3NF in which every determinant is a candidate key.
Must be in 3NF
Boyce-Codd normal form (BCNF)
A process by which a table is changed from a higher-level normal form to a lower-level normal form.
Usually to increase processing speed.
Potentially yields data anomalies
denormalization
A representation of all dependencies within a table.
primary key, partial, or transitive
dependency diagram
Any attribute in a specific row whose value directly determines other values in that row.
determinant
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.
first normal form (1NF)
A table that is in 3NF and contains no multiple independent sets of multivalued dependencies.
fourth normal form (4NF)
The level of detail represented by the values stored in a table’s row.
granularity
Data stored at its lowest level of granularity is said to be atomic data.
An attribute that is not part of a key.
nonprime attribute (nonkey attribute)
A process that assigns attributes to entities so that data redundancies are reduced or eliminated.
normalization
A condition in which an attribute is dependent on only a portion (subset) of the primary key.
partial dependency
An attribute that is part of a key or is the whole key.
prime attribute (key attribute)
In a relation, a characteristic describing a group of multiple entries of the same or multiple types for a single key attribute occurrence.
For example, a car can have multiple colors for its top, interior, bottom, trim, and so on.
repeating group
The second stage in the normalization process, in which a relation is in 1NF and there are no partial dependencies.
Partial dependenies are in only part of the primary key.
second normal form (2NF)
When a table is in 2NF and no nonkey attribute is functionally dependent on another nonkey attribute.
It cannot include transitive dependencies.
third normal form (3NF)
A condition in which an attribute is dependent on another attribute that is not part of the primary key.
transitive dependency
Raw data in its original state.
It might contain redundant data, multivalued data, and/or other data anomalies not found on normalized data relations.
unnormalized data
