Exam 6: Database Design 2: Design Method

If you have alternate keys for a table,you should create a(n) ____________________ index for each alternate key.

An entity-relationship (E-R) model is an approach to representing data in a(n) ____________________.

A natural key is also called a(n) ____ key.

In DBDL,you represent a table by listing all columns and then underlining the primary key.

In an entity-relationship diagram,there is no way to visually determine the primary key.

To obtain information about ____________________ you might ask users questions such as: "If you know a particular employee number,can you establish other information,such as employee name?"

An entity that exists to implement a many-to-many relationship is called a multivalued entity.

If each employee works in a single department and each department has only one employee,the relationship between employees and departments is ____.

An alternative to the primary key of a table is listed with the ____ abbreviation in DBDL.

A secondary key is a column or collection of columns in one table that is required to match the value of the primary key for some row in another table,or be null.

A(n) ____________________ is a special value that represents the absence of a value in a field.

In the standard E-R diagrams,relationships are drawn as ____,with lines connecting the entities involved in relationships.

When creating user views,a "user" can be a report that the system must produce,or a type of transaction the system must support.

There are three different types of primary keys: natural keys,artificial keys,and surrogate keys. Describe each of these types.

Nulls are used when a value is either unknown or inapplicable.

The crucial issue in making the determination between a single many-to-many-to-many relationship and two (or three) many-to-many relationships is the ____.

A(n) ____ is a primary key that consists of a column that uniquely identifies an entity,such as a person's Social Security number.

A subtype is also called a(n) ____ in IDEF1X terminology.

A design that supports all user views is called a normalized design.

A relationship that is necessary for identification is called a(n) ____.