# Database Selection (2025)

> Choose database based on context, not default.

## Decision Tree

```
What are your requirements?
│
├── Full relational features needed
│   ├── Self-hosted → PostgreSQL
│   └── Serverless → Neon, Supabase
│
├── Edge deployment / Ultra-low latency
│   └── Turso (edge SQLite)
│
├── AI / Vector search
│   └── PostgreSQL + pgvector
│
├── Simple / Embedded / Local
│   └── SQLite
│
└── Global distribution
    └── PlanetScale, CockroachDB, Turso
```

## Comparison

| Database        | Best For                       | Trade-offs         |
| --------------- | ------------------------------ | ------------------ |
| **PostgreSQL**  | Full features, complex queries | Needs hosting      |
| **Neon**        | Serverless PG, branching       | PG complexity      |
| **Turso**       | Edge, low latency              | SQLite limitations |
| **SQLite**      | Simple, embedded, local        | Single-writer      |
| **PlanetScale** | MySQL, global scale            | No foreign keys    |

## Questions to Ask

1. What's the deployment environment?
2. How complex are the queries?
3. Is edge/serverless important?
4. Vector search needed?
5. Global distribution required?