What is Database Normalization and How Does it Improve Data Management?

Explaining Database Normalization in Simple English

When asked to define database normalization in a job interview, it's crucial to grasp the concept and convey it concisely. Follow these steps to simplify normalization for non-developers:

1. Eliminate Duplicate Data

Normalization aims to design a database that avoids redundant information. Explain that instead of storing the entire name of countries like "Bosnia & Herzegovina" multiple times for each person in an address list, we can use a reference number to a table containing a list of countries. This reduces the storage space for frequently repeated data.

2. First Normal Form (1NF)

Explain that 1NF ensures every field in a table is atomic, meaning it contains only a single type of information. For example, a phone number should not be duplicated across different fields like "Area Code" and "Number."

3. Second Normal Form (2NF)

2NF further refines the structure by ensuring that every non-primary key field depends on the entire primary key. This means that if we have a table of people's travel history, we would create separate tables for countries and people rather than storing them together. This allows us to update information about a country without affecting any person's data.

4. Key Concepts for Interviewers

When an interviewer asks about normalization in a job interview, they expect you to understand the following key points:

• Avoidance of data repetition
• Definition of atomic data
• Relationship between keys and non-key attributes
• Partitioning tables to maintain data integrity
• Benefits of normalization in terms of data accuracy, storage efficiency, and flexibility

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