Q1. What is MongoDB?
MongoDB is a NoSQL, document-oriented database that stores data in flexible, JSON-like documents (BSON format). Unlike traditional relational databases that use tables and rows, MongoDB uses collections and documents. This makes it highly scalable and suitable for handling large volumes of unstructured or semi-structured data, such as in real-time applications, content management, and mobile apps.
Q2. What are the key features of MongoDB?
Key features include: document-oriented storage (BSON/JSON), high scalability through sharding, built-in replication for high availability, rich query language with dynamic schema, indexing for performance, aggregation framework for data processing, and support for multiple storage engines. It's also schema-less, allowing flexible data models.
Q3. How is MongoDB different from SQL databases?
SQL databases are relational, use fixed schemas, store data in tables with rows and columns, and support JOIN operations. MongoDB is non-relational, uses dynamic schemas, stores data in collections of documents, and handles relationships through embedded documents or references. MongoDB is better for hierarchical data, rapid development, and horizontal scaling.
Q4. What is BSON and how is it related to JSON?
BSON (Binary JSON) is a binary-encoded serialization of JSON-like documents. It extends JSON to include additional data types like Date, Binary, and ObjectId. MongoDB uses BSON to store documents, which allows for efficient encoding, decoding, and traversal. JSON is human-readable, while BSON is optimized for machine parsing and space efficiency.
Q5. What are some common use cases for MongoDB?
MongoDB is commonly used in real-time applications (IoT, gaming), content management systems, e-commerce product catalogs, mobile apps, and log aggregation. Its flexible schema makes it ideal for agile development, while its horizontal scaling supports large-scale data needs. Companies like Forbes, eBay, and Google use MongoDB in various capacities.