UNIT 3 REVIEW

What does a diamond shape represent in an ERD?

• Entity

• Relationship

• Attribute

• Key

What is the purpose of Entity-Relationship Diagrams (ERD) in conceptual data modeling?

• To display the physical design of a database

• To show the attributes of a particular entity

• To depict the relationships between entities

• To create SQL queries

When designing a database, what is cardinality used to describe?

• The number of instances of an entity that can be associated with another entity

• The data type of a field in a table

• The style of the database schema

• The size limit of a table

What is the main type of constraint on relationships?

• Integrity

• Participation

• Multiplicity

• Cardinality

What is a recursive relationship?

• A relationship type that is temporary

• A relationship type in which the same entity type participates more than once in different roles

• A relationship type that never repeats

• A relationship type that is one-time only

To distinguish between a relationship with an attribute and an entity, the rectangle representing the attribute(s) is associated with the relationship using a dashed line.

• TRUE

• FALSE

A relationship type is a set of associations between one or more participating entity types. Each relationship type is given a name that describes its function.

• TRUE

• FALSE

An attribute that holds a single value for each occurrence of an entity type is called a Composite Attribute.

• TRUE

• FALSE

• Entity-Relationship diagram is not suitable for those systems which contain semi-structured or unstructured data set.

• TRUE

• FALSE

• Multivalued Attribute: These attributes allow the user to store multiple different values under the same category for a single entity.

• TRUE

• FALSE