Free ADC Database Management & Normalization Questions and Answers

Question 1

What is the primary purpose of database normalization?

Accepted Answer

To eliminate data redundancy.

Answer

Database normalization is a systematic process of organizing the columns and tables of a relational database to minimize data redundancy and improve data integrity. By breaking down large tables into smaller, related tables and defining relationships, it ensures data is stored efficiently and consistently. This reduces storage space and prevents update anomalies.

Question 2

What does the First Normal Form (1NF) require?

Accepted Answer

Each column contains only atomic values.

Answer

The First Normal Form (1NF) requires that each column in a table contains only atomic, single-valued entries, meaning no repeating groups or multi-valued attributes. Additionally, each row must be uniquely identifiable, typically through a primary key. This foundational step ensures that data is structured in a basic, consistent format, preparing it for further normalization.

Question 3

Which key uniquely identifies a record in a table?

Accepted Answer

Primary key

Answer

A primary key is a column or a set of columns in a table that uniquely identifies each record (row) in that table. It ensures that every row can be distinctly referenced and prevents duplicate records, which is fundamental for maintaining data integrity. Primary keys are also crucial for establishing relationships between different tables in a relational database.

Question 4

What is a foreign key used for?

Accepted Answer

To reference a primary key in another table.

Answer

A foreign key is a column or a set of columns in one table that refers to the primary key in another table. Its main purpose is to establish and enforce a link or relationship between two tables, ensuring referential integrity. This allows for consistent data across related tables and prevents orphaned records, maintaining the database's structural soundness.

Question 5

Which normal form removes partial dependencies?

Accepted Answer

Second Normal Form (2NF)

Answer

The Second Normal Form (2NF) builds upon 1NF by requiring that all non-key attributes in a table be fully functionally dependent on the entire primary key. This means that if a table has a composite primary key, no non-key attribute should depend only on a part of that primary key. This process helps eliminate partial dependencies and further reduces data redundancy.

ADC - Access Data Certification Practice Test

ADC - Access Data Certification Practice Test

Free ADC Database Management & Normalization Questions and Answers