Database Design
Learn to THINK, not copy SQL patterns.
🎯 Selective Reading Rule
Read ONLY files relevant to the request! Check the content map, find what you need.
| File | Description | When to Read |
|------|-------------|--------------|
| database-selection.md | PostgreSQL vs Neon vs Turso vs SQLite | Choosing database |
| orm-selection.md | Drizzle vs Prisma vs Kysely | Choosing ORM |
| schema-design.md | Normalization, PKs, relationships | Designing schema |
| indexing.md | Index types, composite indexes | Performance tuning |
| optimization.md | N+1, EXPLAIN ANALYZE | Query optimization |
| migrations.md | Safe migrations, serverless DBs | Schema changes |
⚠️ Core Principle
- ASK user for database preferences when unclear
- Choose database/ORM based on CONTEXT
- Don't default to PostgreSQL for everything
Decision Checklist
Before designing schema:
- [ ] Asked user about database preference?
- [ ] Chosen database for THIS context?
- [ ] Considered deployment environment?
- [ ] Planned index strategy?
- [ ] Defined relationship types?
Anti-Patterns
❌ Default to PostgreSQL for simple apps (SQLite may suffice) ❌ Skip indexing ❌ Use SELECT * in production ❌ Store JSON when structured data is better ❌ Ignore N+1 queries