Exam 4: Entity Relationship (ER)Modeling

The Crow's Foot model is less implementation-oriented than the Chen model.

The M:N relationship between STUDENT and CLASS must be divided into two 1:M relationships through the use of the ENROLL entity;the ENROLL entity is ____.

In the original Chen model,each attribute is represented using an oval with the attribute name connected to the entity with a line.

A ____ relationship exists when an association is maintained within a single entity.

The Crow's Foot model is more ____________________-oriented than the Chen model.

The ERD represents the ____ database as viewed by the end user.

Connectivities and cardinalities are established by business rules.

A ____ attribute is one that cannot be subdivided.

Relationship strength depends on how the primary key of the related entity is formulated,while the relationship ____________________ depends on how the business rule is written.

Attributes may share a ____.

The Crow's foot symbol with two parallel lines indicates ____ cardinality.

You should always load data from the 1 side of a 1:M relationship.

A ____ attribute can be further subdivided to yield additional attributes.

The DBMS can easily handle multivalued attributes.

The set of possible values for an attribute is a ____.

Some attributes are classified as ____.

A ____ identifier is composed of more than one attribute.

What is a weak relationship? Provide an example.

Software vendors have adopted the Chen representation because of its compact representation.

Failure to understand the distinction between mandatory and optional ____________________ in relationships might yield designs in which awkward (and unnecessary)temporary rows (entity instances)must be created just to accommodate the creation of required entities.