NoSQL Fundamentals
What is NoSQL?
NoSQL (Not Only SQL) databases are non-relational databases designed to handle large volumes of unstructured or semi-structured data. They provide flexible schemas, horizontal scalability, and high performance for specific use cases.
Types of NoSQL Databases
Document Databases
Store data as JSON-like documents. Example: MongoDB, CouchDB
Key-Value Stores
Simple key-value pairs. Example: Redis, DynamoDB
Graph Databases
Optimized for relationships. Example: Neo4j, ArangoDB
Column-Family
Wide-column stores. Example: Cassandra, HBase
When to Use NoSQL
Rapid development with changing requirements
Massive scale with horizontal scaling needs
Flexible or undefined schema
High-speed read/write operations
When to Use SQL
Complex queries with JOINs
ACID compliance requirements
Well-defined, stable schema
Strong consistency requirements
Remember
NoSQL doesn't mean "No SQL" - it means "Not Only SQL". Many applications benefit from using both SQL and NoSQL databases together.