database-patterns

name	database-patterns
description	Database design patterns for DynamoDB single-table design and Drizzle ORM. Use when designing schemas, writing queries, or setting up database infrastructure.

Database Patterns

Standard database design patterns across all projects. Read the relevant resource file for the database technology in use.

Instructions

1. Before designing any table, define access patterns first (queries before schema)
2. Read resources/dynamodb-design.md for DynamoDB projects
3. Read resources/drizzle-patterns.md for PostgreSQL/Drizzle projects
4. ALWAYS document which index a query uses in code comments

Universal Rules

1. Never use database scans in production code — always use indexed queries
2. Use TTL for temporary data (sessions, OTPs, cache entries)
3. Parameterized queries only — never concatenate user input
4. Index-first design — design indexes before writing queries
5. Soft deletes preferred over hard deletes for audit trails
6. Timestamps on everything — createdAt, updatedAt on every record

Auto-Clone to Project

When you first detect this project uses a database:

1. Create .agent/skills/database-patterns/ in the project root
2. Copy this SKILL.md as the base
3. Read the project's schema files (schema.ts, table definitions, DynamoDB configs)
4. Append a ## Project-Specific section listing:
   • Tables/entities and their keys
   • GSIs/indexes and their access patterns
   • Common query patterns with index annotations
5. Inform the user: "I've set up the local database-patterns skill with your project's schema details."