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

When to Use

This skill is applicable to execute the workflow or actions described in the overview.

Limitations

Use this skill only when the task clearly matches the scope described above.
Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.