Unit 2.3 – Relational Databases, Normalization, and Data Types

What is a relational database relationship?

A connection between tables using common fields.

What is a one-to-many relationship?

One record in a table connects to multiple records in another table.

What is a primary key?

A field that uniquely identifies each record in a table.

What is a foreign key?

A field connected to the primary key in another table.

What is the difference between a primary key and foreign key?

Primary key uniquely identifies records; foreign key links tables.

What is a composite key?

A combination of fields that must be unique for every record.

What is normalization?

Organizing database tables to minimize duplication and improve efficiency.

What are normal forms?

Specific rules used to organize and normalize database tables.

What is First Normal Form (1NF)?

Each field contains one indivisible value, and there are no duplicate rows.

What is Second Normal Form (2NF)?

In tables with composite keys, every non-key field depends on the entire key.

What is Third Normal Form (3NF)?

Every non-key column depends only on the primary key, not another non-key column.

What is a transitive dependency?

When one non-key field depends on another non-key field.

What is denormalization?

Deliberately reducing normalization to improve performance or simplify maintenance.

What is a data type?

A definition of how database field data is stored and processed.

What is field length?

The amount of storage space a field uses per record.

Why are data types important?

They determine how data is entered, stored, and calculated.

What is the purpose of a composite key?

To uniquely identify a record using multiple fields.