What is database-schema-designer?

A guide for designing schemas—the tables, fields, relationships, and indexes that define how application data is stored—in SQL or NoSQL databases.

Use it to design entities and relationships, plan migrations and indexes, and create schemas for systems such as shops or user accounts.

It helps avoid poor data structures and database-specific syntax mistakes before implementation begins.

database-schema-designer — Skill for Claude Code by Dannykkh

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add Dannykkh/skill-olympus --skill database-schema-designer

Clone the repo

git clone --depth 1 https://github.com/Dannykkh/skill-olympus

Made for: Claude Code.

Or install skill-olympus, the plugin that ships this one along with the rest of its 98 skills, 7 commands, 42 agents, 5 MCP servers.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/dannykkh/skill-olympus/database-schema-designer/github.svg)](https://agentmods.dev/skills/dannykkh/skill-olympus/database-schema-designer)

Your own site

<a href="https://agentmods.dev/skills/dannykkh/skill-olympus/database-schema-designer"><img src="https://agentmods.dev/badge/skills/dannykkh/skill-olympus/database-schema-designer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/dannykkh/skill-olympus/database-schema-designer"><img src="https://agentmods.dev/badge/skills/dannykkh/skill-olympus/database-schema-designer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,824 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00071	$0.01824
Opus 5	$0.00036	$0.00912
Sonnet 5	$0.00014	$0.00365
Haiku 4.5	$0.00007	$0.00182

Measured 6d ago against content hash 8483e815df06, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

database-schema-designer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/database-schema-designer/SKILL.md · 218 lines

How it starts

The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Schema Designer

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

Quick Start

Just describe your data model:

design a schema for an e-commerce platform with users, products, orders

You'll get a complete SQL schema like:

CREATE TABLE users (
  id BIGINT AUTO_INCREMENT PRIMARY KEY,
  email VARCHAR(255) UNIQUE NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE orders (
  id BIGINT AUTO_INCREMENT PRIMARY KEY,
  user_id BIGINT NOT NULL REFERENCES users(id),
  total DECIMAL(10,2) NOT NULL
);

-- 인덱스는 CREATE TABLE 밖에 분리 (MySQL/PostgreSQL 모두 동작)
CREATE INDEX idx_orders_user ON orders(user_id);

위 예시는 MySQL 기준입니다(AUTO_INCREMENT). PostgreSQL은 PK를 BIGINT GENERATED ALWAYS AS IDENTITY(또는 BIGSERIAL)로 쓰세요. 인덱스는 CREATE INDEX로 분리하면 양쪽에서 동작합니다(인라인 INDEX ...는 MySQL/MariaDB 전용 → Postgres 문법 에러). 이 스킬은 DB-First라 대상 DB에 맞춰 설계가 달라집니다.

What to include in your request:

Entities (users, products, orders)
Key relationships (users have orders, orders have items)
Scale hints (high-traffic, millions of records)
Database preference (SQL/NoSQL) - defaults to SQL if not specified

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"

Key Terms

Term	Definition
Normalization	Organizing data to reduce redundancy (1NF → 2NF → 3NF)
3NF	Third Normal Form - no transitive dependencies between columns
OLTP	Online Transaction Processing - write-heavy, needs normalization
OLAP	Online Analytical Processing - read-heavy, benefits from denormalization
Foreign Key (FK)	Column that references another table's primary key
Index	Data structure that speeds up queries (at cost of slower writes)
Access Pattern	How your app reads/writes data (queries, joins, filters)
Denormalization	Intentionally duplicating data to speed up reads

Read the full file on GitHub · 218 lines

Files

What ships with it

10 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

6d ago First seen · 218 lines · 71 tokens per session scan A 8483e815df06

Subscribe to this mod's changes

database-schema-designer is a skill published in the GitHub repository Dannykkh/skill-olympus (5 stars, last pushed today), licensed MIT. It adds 71 tokens to every session and 1,824 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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