SQL vs NoSQL
Contrasting structured relational storage against highly elastic, denormalized non-relational engines.
What you'll learn
- SQL (Relational)
- NoSQL (Non-relational)
- ACID
- BASE
TL;DR
Contrasting structured relational storage against highly elastic, denormalized non-relational engines.
Visual System Topology
SQL vs NoSQL Structure
SQL (Relational)
| id | name |
|---|---|
| 1 | Alice |
| id | user_id | city |
|---|---|---|
| 101 | 1 | New York |
NoSQL (Document)
Concept Overview
SQL (Structured Query Language) databases store data in structured tables with predefined schemas, while NoSQL databases use flexible data models like documents, key-value pairs, or graphs.
The choice between SQL and NoSQL depends on your data structure, consistency requirements, and scaling needs.
Key Architectural Pillars
SQL (Relational)
Data in tables with rows and columns. Fixed schema. Relationships via foreign keys. ACID transactions. Examples: PostgreSQL, MySQL, Oracle.
NoSQL (Non-relational)
Flexible schema. Multiple data models: Document (MongoDB), Key-Value (Redis), Column (Cassandra), Graph (Neo4j). BASE properties.
ACID
Atomicity, Consistency, Isolation, Durability. Guarantees for SQL transactions ensuring data integrity.
BASE
Basically Available, Soft state, Eventually consistent. NoSQL trade-off: availability over immediate consistency.