What are the 3 main types of databases?

Databases are the backbone of modern data management, allowing organizations to store, retrieve, and manage vast amounts of information efficiently. While there are various types of databases available, they can generally be categorized into three main types: relational databases, NoSQL databases, and NewSQL databases. Each type has its own characteristics and use cases, making them suitable for different scenarios. Here are some common DBMS interview questions that you may encounter during a job interview

Relational Databases (RDBMS):

Structure:

Relational databases organize data into structured tables with rows and columns. Each table represents a specific entity, and the relationships between entities are established through keys.

ACID Compliance:

Relational databases adhere to the ACID (Atomicity, Consistency, Isolation, Durability) properties, ensuring data integrity and consistency.

SQL Language:

They use Structured Query Language (SQL) for querying and managing data. SQL provides a powerful and standardized way to interact with the database.

Use Cases:

RDBMS are ideal for scenarios where data structure is well-defined and unlikely to change frequently. They are widely used in traditional business applications, such as financial systems and customer relationship management (CRM) software.

NoSQL Databases:

Structure:

NoSQL databases are designed to handle unstructured or semi-structured data. They do not rely on the rigid tabular structure of RDBMS and allow more flexibility in data storage.

Scalability:

NoSQL databases excel in horizontal scalability, making them suitable for applications that require rapid growth and flexibility. They are well-suited for big data, real-time applications, and distributed systems.

Types:

NoSQL databases come in several types, including document-oriented (e.g., MongoDB), key-value stores (e.g., Redis), column-family stores (e.g., Cassandra), and graph databases (e.g., Neo4j).

Use Cases:

NoSQL databases are commonly used in web applications, content management systems, IoT, and situations where data models may evolve rapidly.

NewSQL Databases:

Structure:

NewSQL databases attempt to combine the scalability of NoSQL databases with the ACID compliance of traditional relational databases. They are designed to handle the demands of modern, highly distributed applications.

ACID Compliance:

Unlike traditional RDBMS, NewSQL databases maintain strong ACID guarantees while providing horizontal scalability.

Examples:

Google Spanner and CockroachDB are examples of NewSQL databases that aim to balance the best of both worlds.

Use Cases:

NewSQL databases are suitable for applications that require both the consistency of traditional databases and the scalability of NoSQL, particularly in large, distributed, and global environments.

Conclusion

Choosing the right database type depends on the specific requirements of an application. It's essential to consider factors such as data structure, scalability needs, data complexity, and the desired level of consistency. Relational databases remain the foundation of many established systems, but NoSQL and NewSQL databases have gained popularity due to their ability to handle the ever-evolving landscape of modern data management. We've covered a comprehensive list of interview questions on DBMS. These questions, ranging from fundamentals to advanced topics, will enable you to showcase your knowledge and expertise in the field, increasing your chances of acing your DBMS interview.