Background and Context
The landscape of database selection for small applications has shifted. With SQLite 3.45 and the rise of edge computing, the boundary between local and server databases has blurred. SQLite is an in-process library storing the entire database in one file, eliminating the need for a separate server process. PostgreSQL 16 remains the gold standard for multi-user relational databases. When building a small app today, you are no longer choosing between simple and professional, but rather between serverless architecture and robust scalability. Modern tools like Litestream have solved the backup and replication hurdles that once plagued SQLite, making it a viable contender for production SaaS products.
Key Differences
Understanding technical nuances is critical for a senior developer. PostgreSQL utilizes a process-per-connection model with Multi-Version Concurrency Control (MVCC), allowing high-volume concurrent reads and writes across CPU cores. SQLite uses a simpler locking mechanism. While the default mode allows only one writer at a time, turning on Write-Ahead Logging (WAL) mode enables multiple readers and one writer simultaneously.
- Concurrency: Postgres handles hundreds of simultaneous writers; SQLite is optimized for high-read, low-write scenarios.
- Data Integrity: Postgres enforces strict schemas and types; SQLite uses manifest typing unless STRICT mode is enabled.
- Extensions: Postgres offers powerful tools like PostGIS for spatial data or pgvector for AI; SQLite extensions are harder to manage.
- Management: Postgres requires roles and connection pooling; SQLite requires zero configuration.
Real-World Use Cases
For small apps, the choice depends on the deployment