database-schema-designer

name	database-schema-designer
description	This skill should be used when designing database schemas for SQL or NoSQL databases. It provides normalization guidelines, indexing strategies, migration patterns, and performance optimization.
argument-hint	[domain or requirements]
allowed-tools	Read
agent	database-designer
context	fork
metadata	{"triggers":"database schema, schema design, SQL design, NoSQL design, ERD, database design, create tables, model data, data modeling","related-skills":"architecture-design, java-spring-api, nestjs-api, python-dev","domain":"infrastructure","role":"architect","scope":"design","output-format":"document"}
last-reviewed	2026-03-14

Iron Law

NO SCHEMA MIGRATION WITHOUT A DOWN (ROLLBACK) SCRIPT AND AN INDEX ON EVERY FOREIGN KEY — unindexed FKs cause full table scans; irreversible migrations cause production incidents

Database Schema Designer

Design production-ready database schemas with best practices built-in.

Triggers

Trigger	Example
design schema	"design a schema for user authentication"
database design	"database design for multi-tenant SaaS"
create tables	"create tables for a blog system"
schema for	"schema for inventory management"
model data	"model data for real-time analytics"
I need a database	"I need a database for tracking orders"
design NoSQL	"design NoSQL schema for product catalog"

Quick Reference

Task	Approach	Key Consideration
New schema	Normalize to 3NF first	Domain modeling over UI
SQL vs NoSQL	Access patterns decide	Read/write ratio matters
Primary keys	INT or UUID	UUID for distributed systems
Foreign keys	Always constrain	ON DELETE strategy critical
Indexes	FKs + WHERE columns	Column order matters
Migrations	Always reversible	Backward compatible first

Process

Phase 1: Analyze

• Identify entities and relationships
• Determine access patterns (read-heavy vs write-heavy)
• Choose SQL or NoSQL based on requirements

Phase 2: Design

• Normalize to 3NF (SQL) or determine embed/reference strategy (NoSQL)
• Define primary keys and foreign keys
• Choose appropriate data types -- read reference/data-types-reference.md for type guides