Exam 2: The Relational Model

Briefly describe the various tasks of the primary key.

What is normalization?

The primary key is used both to identify unique rows in a relation and to represent rows in relationships.

The unique keys that are not chosen to be the primary key are called ________ keys.

Explain the concept of a surrogate key.

What are the basic steps of the normalization process?

A key that contains more than one attribute is called a(n):

In Microsoft Access,a relationship is created by dragging a foreign key column and dropping it on top of the corresponding primary key.

The first step of the normalization process is to:

Every cell in a relation can hold only a single value.

Every relation is a table,but not every table is a relation.

Explain the terms relation,tuple,and attribute.

Any table that meets the requirements of a(n)________ is in first normal form.

In Microsoft Access,the relationship between two tables is not actually created until:

Explain the possible interpretations of a null value.

A(n)________ is a unique,numeric value that is appended to the relation to serve as the primary key.

Which of the following functional dependency diagrams accurately represents the following situation: •A campus has many buildings. •Each building has a unique name. •Each building has many rooms. •All rooms in any given building are numbered sequentially starting at "101." •Each room has a certain capacity,although many rooms in the same building or different buildings may have the same capacity. •Each room is assigned to a single department. •A department may have many rooms in one or more buildings,each with the same or different capacities.

To be considered a composite key,a key must contain at least two attributes.

The first step of the normalization process is to identify all the candidate keys of a relation.

In Microsoft Access,foreign keys are designated by using the Foreign Key button in the toolbar.