database-schema SKILL.md skillA
database-schema from skillmedev/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add skillmedev/skills/database-schema@git:20261005.bea4ea5Pins git:20261005.bea4ea5 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- skillmedev/skills
- Path
skills/database-schema/SKILL.md- Versions recorded
- 3
- Latest version
- git:20261005.bea4ea5, committed Oct 5, 2026
- First version recorded
- Jul 5, 2026
- Size
- 8,635 bytes
- Repository stars
- 19
- License
- MIT
Designs normalized, constrained, migration-friendly relational schemas - entity modeling, key and type selection, indexes derived from real query patterns, and safe forward/rollback migrations. Use when someone asks "design a schema for X", "should I normalize or denormalize this", "what should my primary key be", "how do I add this column without downtime", or "why is my unique constraint broken with soft deletes". Do NOT use for tuning a slow query on an existing schema - use…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Database Schema Designer A schema is the one part of a system you cannot refactor with a find-and-replace: every shortcut taken at design time becomes a locked-table migration on a hot production database later. This skill produces schemas that stay correct and fast as data grows - invalid states unrepresentable, indexes matched to real queries, and every change shippable without downtime. ## Operating procedure Follow the steps in order. Constraints come before indexes because constraints define correctness and indexes only define speed; migrations come last because they depend on both. ### Step 1: Gather inputs Collect these before writing any DDL. If a number is a guess, label it a guess and proceed. 1. Entities and relationships - nouns of the domain and their cardinality (1:1, 1:N, M:N). 2. The top 5-10 queries by expected frequency, with their filter and sort columns. Indexes come from this list, not from intuition. 3. Expected row counts at 1 year and 3 years per table, and read:write ratio per hot table. Default assumption if unknown: 10:1 read-heavy. 4. Multi-tenancy - single tenant, or `tenant_id` on every row? …
Read the whole file at its exact version.
How to install
mdr add skillmedev/skills/database-schema@sha256:a245d8585a37d48fThe line at the top of this page pins the label git:20261005.bea4ea5, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ta6qcpisnyensyby)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Jul 5, 2026 and Oct 5, 2026, about one every 46 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261005.bea4ea5 latest | 2026-10-05 | bea4ea5 | 8,635 B | A | view · diff |
| git:20260705.a28c4ce | 2026-07-05 | a28c4ce | 8,598 B | A | view · diff |
| git:20260705.acb5571 | 2026-07-05 | acb5571 | 8,630 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (8635 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
skillmedev/skills · 19 stars · license MIT · pushed 2026-10-13 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ta6qcpisnyensyby GET https://markdownregistry.com/api/v1/resolve?ref=skillmedev/skills/database-schema GET https://markdownregistry.com/api/v1/blob/a245d8585a37d48f5f328cc464d720eb2d39a1b4a85f160fbfa04346a6f7189e
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.