Author Archives: Stanislav_Panteleev

Denormalization is the process of intentionally introducing redundancy into a database by combining normalized tables — often for performance or simplicity reasons. It’s the reverse of normalization, done not because of bad design, but to optimize read-heavy operations. 🎯 Why … Continue reading →

📘 Third Normal Form (3NF) A table is in 3NF if: ✅ It is in 2NF ✅ It has no transitive dependencies — i.e., non-key columns do not depend on other non-key columns 🔍 What is a Transitive Dependency? A … Continue reading →

Absolutely! Let’s walk through a clear example where a composite key is used, and no partial dependency exists — meaning the table is in 2NF. ✅ Example: No Partial Dependency (2NF is satisfied) Table: ExamResults StudentID ExamID Score 1 101 … Continue reading →

📗 Second Normal Form (2NF) 2NF (Second Normal Form) builds on 1NF and adds one more rule: A table is in 2NF if: It is in 1NF, and All non-key attributes are fully functionally dependent on the entire primary key. … Continue reading →

📘 First Normal Form (1NF) 1NF (First Normal Form) is the basic level of normalization.A table is in 1NF if: All columns contain atomic (indivisible) values Each row is unique Each column contains values of a single type There are … Continue reading →

📚 What is Normalization in Databases? Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. It involves dividing large, complex tables into smaller, related tables and defining relationships between them. 🎯 Goals … Continue reading →

A foreign key is a column (or set of columns) in one table that refers to the primary key in another table. It is used to establish a relationship between two tables and enforce referential integrity. 🔁 Purpose of a … Continue reading →

A primary key is a column or a set of columns in a table that uniquely identifies each row.It ensures that: No two rows have the same value in the primary key. The key value is never NULL. ✅ Example: … Continue reading →

🔑 1. Simple Key A single attribute (column) that uniquely identifies a record. Example:In a Users table, user_id is a simple key if it alone uniquely identifies each user. 🧩 2. Composite Key A combination of two or more attributes … Continue reading →

The relational data model is a way to organize data in a database using tables (also called relations). It was introduced by E. F. Codd in 1970 and is the foundation of relational databases like MySQL, PostgreSQL, and Oracle. 🧱 … Continue reading →