SQL vs NoSQL: Complete Comparison Guide
Compare SQL and NoSQL databases on data structure, scalability, consistency, and use cases. Discover which database paradigm best fits your application.
SQL Databases
Relational databases that store data in structured tables with rows and columns connected by relationships. SQL databases use Structured Query Language for data manipulation and provide strong ACID guarantees. Examples include PostgreSQL, MySQL, and SQL Server.
NoSQL Databases
A broad category of non-relational databases that store data in flexible formats such as documents, key-value pairs, graphs, or columns. NoSQL databases are designed for horizontal scalability and flexible schemas. Examples include MongoDB, Redis, Cassandra, and Neo4j.
Comparison table
| Feature | SQL Databases | NoSQL Databases |
|---|---|---|
| Data structure | Fixed schema — tables with defined columns and data types | Flexible schema — documents, key-value, graphs, or columns |
| Scalability | Primarily vertical — horizontal is complex but possible | Designed for horizontal scaling across multiple nodes |
| Consistency | Strong — ACID transactions guarantee data integrity | Configurable — from eventual consistency to strong consistency |
| Query capabilities | Powerful — complex JOINs, subqueries, and aggregations | Variable — depends on the type of NoSQL database |
| Relationships | Built-in — foreign keys and JOINs for complex relationships | Limited — denormalization or application-level joins required |
Verdict
The choice between SQL and NoSQL is not about better or worse, but about the right tool for the right job. SQL databases are the standard for applications with structured data, complex relationships, and strict consistency requirements. NoSQL databases excel when horizontal scalability, flexible schemas, and high throughput are priorities. Modern SQL databases like PostgreSQL have narrowed the gap with JSON support and better scaling options. Many successful applications use both paradigms side by side, each for its strengths.
Our recommendation
At MG Software, we default to PostgreSQL (SQL) as our primary database for its versatility, reliable ACID transactions, and the excellent Supabase platform. PostgreSQL's JSONB support allows us to store document-like data when needed without a separate NoSQL database. For specific use cases like caching, we use Redis (NoSQL), and for search functionality, we consider Elasticsearch. We only recommend a NoSQL-first approach when the use case truly demands horizontal scaling or schema flexibility as a primary requirement.
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