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name: database-design description: Database design principles and decision-making. Schema design, indexing strategy, ORM selection, serverless databases. allowed-tools: Read, Write, Edit, Glob, Grep

Database Design

Learn to THINK, not copy SQL patterns.

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⚠️ Core Principle

• ASK user for database preferences when unclear
• Choose database/ORM based on CONTEXT
• Don't default to PostgreSQL for everything

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Decision Checklist

Before designing schema:

• Asked user about database preference?
• Chosen database for THIS context?
• Considered deployment environment?
• Planned index strategy?
• Defined relationship types?

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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