# Database Design

Designs database schemas, indexing strategies, query optimization, and migration...

- Repository: https://github.com/CloudAI-X/claude-workflow-v2 (1421 stars)
- Category: Design
- License: MIT
- Last updated: 2026-10-06
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add CloudAI-X/claude-workflow-v2 --skill database-design -g -a claude-code -y`
Codex: `npx skills add CloudAI-X/claude-workflow-v2 --skill database-design -g -a codex -y`
Cursor: `npx skills add CloudAI-X/claude-workflow-v2 --skill database-design -g -a cursor -y`
Gemini CLI: `npx skills add CloudAI-X/claude-workflow-v2 --skill database-design -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add CloudAI-X/claude-workflow-v2`

## Description

Designs database schemas, indexing strategies, query optimization, and migration patterns for SQL and NoSQL databases. Use when designing tables, optimizing queries, fixing N+1 problems, planning migrations, or when asked about database performance, normalization, ORMs, or data modeling.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Database Design

### When to Load

- **Trigger**: Schema design, migrations, query optimization, indexing strategies, data modeling, N+1 fixes
- **Skip**: No database work involved in the current task

## Database Design Workflow

Copy this checklist and track progress:

```
Database Design Progress:
- [ ] Step 1: Identify entities and relationships
- [ ] Step 2: Normalize schema (3NF minimum)
- [ ] Step 3: Evaluate denormalization needs
- [ ] Step 4: Design indexes for query patterns
- [ ] Step 5: Write and optimize critical queries
- [ ] Step 6: Plan migration strategy
- [ ] Step 7: Configure connection pooling
- [ ] Step 8: Validate against anti-patterns checklist
```

## Schema Design Principles

### Normalization Forms

```
1NF: Atomic values, no repeating groups
2NF: 1NF + no partial dependencies (all non-key columns depend on full PK)
3NF: 2NF + no transitive dependencies (non-key columns don't depend on other non-key columns)
```

```sql
-- WRONG: Unnormalized
CREATE TABLE orders (
  id SERIAL PRIMARY KEY,
  customer_name TEXT,
  customer_email TEXT,        -- duplicated across orders
  product1_name TEXT,         -- repeating groups
  product1_qty INT,
  product2_name TEXT,
  product2_qty INT
);

-- CORRECT: Normalized to 3NF
CREATE TABLE customers (
  id SERIAL PRIMARY KEY,
  name TEXT NOT NULL,
  email TEXT UNIQUE NOT NULL
);

CREATE TABLE orders (
  id SERIAL PRIMARY KEY,
  customer_id INT REFERENCES customers(id),
  created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE TABLE order_items (
  id SERIAL PRIMARY KEY,
  order_id INT REFERENCES orders(id),
  product_id INT REFERENCES products(id),
  quantity INT NOT NULL CHECK (quantity > 0)
);
```

### When to Denormalize

Denormalize only when you have measured proof of performance issues:

```sql
-- Acceptable denormalization: precomputed counter to avoid COUNT(*)
ALTER TABLE posts ADD COLUMN comment_count INT DEFAULT 0;

The rest: https://github.com/CloudAI-X/claude-workflow-v2/blob/HEAD/skills/database-design/SKILL.md