ecto-n1-check SKILL.md skillA

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ecto-n1-check from oliver-kriska/claude-elixir-phoenix is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

mdr add oliver-kriska/claude-elixir-phoenix/ecto-n1-check@git:20260929.c08ad14

Pins git:20260929.c08ad14 in mdr.lock. Pin the fingerprint instead.

Audit grade

A, 17 of 17 checks passed

Kind

SKILL.md skill

Repository

oliver-kriska/claude-elixir-phoenix

Path

targets/dsh/skills/ecto-n1-check/SKILL.md

Versions recorded

2

Latest version

git:20260929.c08ad14, committed Sep 29, 2026

First version recorded

Aug 27, 2026

Size

2,102 bytes

Repository stars

573

License

MIT

Detect N+1 query anti-patterns specifically — Repo calls inside Enum/for.

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

# N+1 Query Detection

Identify and fix N+1 query anti-patterns in Ecto/Phoenix applications.

## Iron Laws - Never Violate These

1. **Never access associations without preload** - Always preload before `Enum.map`
2. **No Repo calls inside loops** - Restructure to batch queries
3. **Preload at context boundary** - Load associations in context, not controllers/views
4. **Use joins for filtering** - Use `join` + `preload` when filtering by association

## Detection Patterns

### Pattern 1: Enum.map with Repo

```elixir
# BAD: N+1 queries
users
|> Enum.map(fn user -> Repo.get(Order, user.order_id) end)

# GOOD: Single query with preload
users
|> Repo.preload(:orders)
```

### Pattern 2: Association Access Without Preload

```elixir
# BAD: Lazy loading triggers N queries
for user <- users do
  user.posts  # Triggers query for each user!
end

# GOOD: Eager load first
users = Repo.all(User) |> Repo.preload(:posts)
for user <- users do
  user.posts  # Already loaded
end
```

### Pattern 3: Nested Association Access

```elixir
# BAD: N+1 for nested associations
user.posts |> Enum.map(fn post -> post.comments end)

# GOOD: Nested preload
Repo.preload(user, posts: :comments)
```
…

Read the whole file at its exact version.

How to install

mdr add oliver-kriska/claude-elixir-phoenix/ecto-n1-check@sha256:6c6b6671033c3ced

[![mdr](https://markdownregistry.com/badge/art_r33g6azqmct7opqo.svg)](https://markdownregistry.com/a/art_r33g6azqmct7opqo)

Versions

The registry has recorded 2 versions of this file, between Aug 27, 2026 and Sep 29, 2026, about one every 33 days.

Audit of the latest version

Source

API

GET https://markdownregistry.com/api/v1/artifacts/art_r33g6azqmct7opqo
GET https://markdownregistry.com/api/v1/resolve?ref=oliver-kriska/claude-elixir-phoenix/ecto-n1-check
GET https://markdownregistry.com/api/v1/blob/6c6b6671033c3ced9937abb6d0e9aeedded872ac27818f29320fbff6171ee03c

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.

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