Relational Database Model Quiz

What is the relational model based on?

• Predicate logic and set theory

• Mathematics and statistics

• Computer science and programming

• Data structures and algorithms

What does a table (relation) represent?

• A one-dimensional structure

• A two-dimensional structure

• A three-dimensional structure

• A linear structure

What is the primary key in the STUDENT table?

• STU_NUM

• STU_LNAME

• STU_FNAME

• STU_SECT

What is a composite key?

• A key that is composed of more than one attribute

• A key that is unique for each row

• A key that is used for data retrieval

• A key that cannot contain null entries

What is the purpose of entity integrity?

• To ensure all primary key entries are unique

• To allow null entries in primary keys

• To maintain referential integrity

• To ensure data retrieval is efficient

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

• To ensure each row has a unique identity

• To allow null entries in the table

• To link tables together

• To store duplicate values

What does referential integrity ensure in a database?

• All foreign keys must be null

• Foreign keys must reference existing primary keys

• Primary keys can be duplicated

• Foreign keys can have any value

What happens if a primary key has mandatory matching foreign key values in another table?

• You can delete the row in the first table

• You cannot delete the row in the first table

• You can update the primary key

• You can ignore the foreign key

What is the purpose of using flags in a database?

• To indicate the absence of some value

• To store duplicate entries

• To create new tables

• To enforce primary key constraints

What is relational algebra?

• A set of mathematical principles for manipulating tables

• A programming language for databases

• A type of database management system

• A method for creating new tables