Relational Database Week 09

What is the main function of a foreign key in a database?

• To store large amounts of data

• To link tables together

• To create user interfaces

• To encrypt data

What is a primary key in a database?

• A set of one or more columns that makes each row unique

• A column that stores encrypted data

• A column that allows duplicate values

• A set of columns that increases data redundancy

What do arrows in a one-to-many relationship indicate?

• A single connection

• Multiple connections

• No connection

• A circular connection

What is the purpose of having a composite primary key in a junction table?

• To ensure each record is unique without adding a third ID column.

• To allow duplicate records in the table.

• To simplify the table structure by removing foreign keys.

• To increase the number of columns in the table.

What does the term "composite primary key" refer to?

• A primary key made up of multiple columns

• A single unique column

• A CSV file used to populate tables

• A script for creating and inserting data

What is a surrogate primary key?

• A natural key used in the external world.

• A primary key that is a combination of multiple columns.

• An auto-incrementing number with no real significance.

• A key that is dependent on other columns.

What is the additional requirement for a table to be in Third Normal Form (3NF) beyond meeting the criteria for 2NF?

• All non-key attributes must be independent of other non-key attributes

• The table must not have any foreign keys

• All non-key attributes must depend on at least one part of the primary key

• The table must have a composite primary key

What prevents the table from being in third normal form?

• It has a composite primary key.

• It has a transitive functional dependency.

• It contains atomic data.

• It has no primary key.

How can a transitive functional dependency be resolved in a database table?

• By creating a new table to separate the attributes involved in the transitive dependency

• By combining the dependent attributes into a single column

• By removing all foreign key constraints from the table

• By ensuring that the table has a composite primary key