PostgreSQL
What it is: Most advanced open-source relational database. JSONB support, full-text search, PostGIS for geo, extensions for everything.
What It Does Best
ACID compliance. Transactions work. Data integrity guaranteed. No surprises.
Flexible data types. JSON, arrays, ranges, custom types. SQL for structured + NoSQL for flexibility.
Extensions ecosystem. PostGIS for maps, TimescaleDB for time series, pgvector for AI embeddings.
Pricing
Free. Open source, PostgreSQL license.
When to Use It
✅ General-purpose database needs
✅ Complex queries and relationships
✅ Mixed structured + semi-structured data
✅ Need reliability and data integrity
When NOT to Use It
❌ Analytics on massive datasets (use data warehouses)
❌ Extreme scale reads (consider NoSQL + caching)
❌ Document-only storage (MongoDB simpler)
Bottom line: Default choice for relational database. Free, powerful, and keeps getting better. If unsure what database to use, choose Postgres.