Table of Contents

Domain

set of allowed values for an attribute

Atomicity

Attribute values should be atomic i.e. indivisible

Database Keys

Super Key

Candidate Key

• Unique
• can be null as opposed to primary key

Primary Key

Secondary Key

All candidate keys that have not been selected as the primary key are called secondary keys

Surrogate / Synthetic Key

a key that uniquely identifies an entity or an object in the database; however, it is not derived from the application data

Foreign Key

Compound Key

Relational Operators

Select (selection of rows)