Relational Database Model Quiz

What is the relational model based on?

• Predicate logic and set theory

• Only set theory

• Only predicate logic

• None of the above

What does a table (relation) represent?

• A one-dimensional structure

• A two-dimensional structure

• A three-dimensional structure

• None of the above

What is a primary key?

• A key that can contain null entries

• A candidate key selected to uniquely identify all other attribute values

• A superkey without any unnecessary attributes

• None of the above

What is functional dependence?

• The value of one or more attributes determines the value of one or more other attributes

• The state in which knowing the value of an attribute makes it possible to determine the value of another

• Both A and B

• None of the above

What is the purpose of integrity rules?

• To maintain a good database design

• To ensure all data is consistent

• Both A and B

• None of the above

What is an example of a foreign key?

• STU_NUM

• STU_SECT

• STU_LNAME

• STU_FNAME

What does entity integrity ensure?

• Each row in a table has its own unique identity

• All primary key entries are unique

• Both A and B

• None of the above

What is the purpose of a primary key in a database?

What does referential integrity ensure in a database?

What happens if a foreign key has a null entry?