DBMS Interview Questions

DBMS stands for Database Management System — a software system that allows defining, creating, maintaining, and controlling access to databases.

It manages data efficiently and ensures data integrity, security, and concurrency control.

Functions include data storage, retrieval, query processing, transaction management, and backup/recovery.

DBMS acts as an interface between users and the physical database, enabling structured and secure data access.

ACID properties ensure reliable transactions in a database management system.

They stand for Atomicity, Consistency, Isolation, and Durability.

Atomicity ensures all-or-nothing execution of transactions.

Consistency maintains valid state transitions of data according to defined rules.

Isolation ensures that transactions execute independently and transparently.

Durability guarantees that committed transactions remain permanent even in case of system failure.

ACID compliance is critical for financial systems, e-commerce, and mission-critical applications.

Normalization is the process of organizing data in a database to reduce redundancy and dependency by dividing large tables into smaller, logically related ones.

It follows normal forms like 1NF, 2NF, 3NF, BCNF, and 4NF to ensure data integrity and minimize anomalies during insertions, updates, and deletions.

Normalization improves scalability, reduces data duplication, and ensures consistent relationships between entities.

However, over-normalization can lead to complex queries and reduced performance, so a balance is often required.