Chapter 14 Normalization

Define Unnormalized Form (UMF)

A table that contains one or more repeating groups

What is full functional dependence?

Indicates that is A and B are attributes of a relation, then B is fully functionally dependent on A

How can normalization help with validation ?

By checking the structure of relations

What is Second Normal form (2NF) ?

A relation that is in first normal form and every non-primary-key attribute is fully functionally dependent on the primary key

What is third normal form (3NF)

A relation that is in first normal form and second normal form and in which no non-primary-key attributes is transitively dependent on the primary-key

What is First Normal form ?

A relationship in which the intersection of each row and column contains one and only one value.

What is Normalization?

A technique for producing a set of relations with desirable properties, given the data requirements of an enterprise. With a major goal of reducing data redundancy.

What is decomposition ?

Decomposition is the process of breaking down in parts or elements. It replaces a relation with a collection of smaller relations. It breaks the table into multiple tables in a database.

What is functional dependency ?

Describes the relationships between attributes

What is functional dependency ?

Describes the relationships between attributes.

What are benefits of normalization/ a suitable set of relations ?

Easier for the user to access and maintain data; via updating, deleting, inserting... Take up minimal storage space on the computer

Name three types of updates anomalies ?

Insertion Deletion Modifcations

Define Lossless-join property

Lossless-join property enables us to find any instance of the original relation from corresponding instances in the smaller relation

Data rundancy exist when ?

Multiple class of an attribute exist within a table Multiple values are not required to establish the relationships between the attributes and the table

What are potential benefits for implemented databases ?

Reduction in the file storage space required by the base relations thus minimizing costs. Updates to the database stored in the database are achieved with a minimal number of operations thus reducing the opportunities for data inconsistencies

Define determinant

The attribute on the left side of the arrow of a functional dependency.

What does the determinant of a functional dependency refer to ?

The attributes or group of attributes on the left-hand side of the arrow

What are some of a suitable set of relations ?

The minimal number of attributes necessary to support the data requirements Attributes with a close logical relationship are found in the same relation Minimal redundancy with each attribute represented only once with the important expectation of attributes that form all or part of the foreign key

What are characteristics of functional dependencies ?

There is a one to one relationship between attribute(s) on the left hand side and those on the right hand side of a functional dependence It will hold for all time The determinant has the minimal number of attributes necessary to maintain the dependency with the attribute(s) on the right hand side

What is the Dependency preservation property ?

This enables us to enforce a constraint on the original relation by enforcing some constraints on each of the smaller relations

What is the dependency preservation ?

This ensues that a constraint on the original relation can be maintained by simply enforcing some constraint on each of the smaller relations. In other words we do not need to preform joins on smaller relations to check whether a constraint on the original relation is violated.

What is the lossless-join property of modification ?

This ensures that any instance of the original relation can be identified from corresponding instances in the smaller relations.

What is the bottom-up approach ?

This is creating a set of relations from scratch

Define top-down approach

This is working with a finished systems and breaking it to rebuild it.

True or False relations that contain redundant information may potentially suffer from update anomalies ?

True

True or false determinants should have the minimal number of attributes necessary to maintain the functional dependency with the attributes on the right hand-side ?

True