schema-antipatterns SKILL.md skillA
schema-antipatterns from sigistry/marketplace is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add sigistry/marketplace/schema-antipatterns@git:20260826.571bc2fPins git:20260826.571bc2f in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- sigistry/marketplace
- Path
plugins/sql-safety-net/skills/schema-antipatterns/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260826.571bc2f, committed Aug 26, 2026
- First version recorded
- Jul 8, 2026
- Size
- 3,639 bytes
- Repository stars
- 3
- License
- MIT
This skill should be used when the user mentions "schema design", "database anti-pattern", "N+1", "foreign key index", "normalization", "data types", "constraints", "ORM performance", "missing primary key", "VARCHAR 255", "boolean as int", or reviewing DDL/models for design problems. It provides a relational schema design anti-pattern catalog plus a per-ORM N+1 pattern library.
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
# Schema Antipatterns ## Purpose Provide a standardized catalog of relational schema design anti-patterns and ORM query anti-patterns, so schema reviews and N+1 hunts are consistent and grounded, statically, from DDL and source, with no database connection. These are the recurring mistakes that a DBA would flag on sight and that a team without one re-introduces every sprint. ## Schema anti-pattern catalog | Category | Anti-pattern | Why it bites | Correct choice | |---|---|---|---| | Keys | No primary key | No stable row identity; replication/tooling breaks | Surrogate `bigint`/`identity` or `uuid` PK | | Keys | UUID stored as `varchar(36)` | 2–3× storage, slow joins | `uuid` (PG) / `BINARY(16)` (MySQL) | | Foreign keys | FK column with no index | Every parent delete/join scans the child | Index every FK column | | Foreign keys | Relationship with no FK constraint | Orphan rows, no referential integrity | Declare the FK (+ `ON DELETE` action) | | Types | Money as `float`/`double` | Rounding errors on cents | `numeric(12,2)` / `DECIMAL` | | Types | `timestamp` without time zone | Ambiguous instants across zones/DST | `timestamptz` (PG) / store UTC + document | …
Read the whole file at its exact version.
How to install
mdr add sigistry/marketplace/schema-antipatterns@sha256:fcd3bf773b8f898eThe line at the top of this page pins the label git:20260826.571bc2f, 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_efsqi3msq4notw7y)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Jul 8, 2026 and Aug 26, 2026, about one every 24 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260826.571bc2f latest | 2026-08-26 | 571bc2f | 3,639 B | A | view · diff |
| git:20260715.fcd8714 | 2026-07-15 | fcd8714 | 3,639 B | A | view · diff |
| git:20260708.c0884a9 | 2026-07-08 | c0884a9 | 3,663 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 (3639 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
sigistry/marketplace · 3 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_efsqi3msq4notw7y GET https://markdownregistry.com/api/v1/resolve?ref=sigistry/marketplace/schema-antipatterns GET https://markdownregistry.com/api/v1/blob/fcd3bf773b8f898e5a04b99a3bd1759121864e3544dd787ec4634fa295834fbf
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.