database-deity

A database performance guide for SQL queries and ORM code, where an ORM is a tool that lets code work with database records. It examines query plans, indexes, and repeated queries inside loops.

In plain words
What is it for?
Use it to analyze slow queries, inspect or infer needed indexes, find queries inside loops, and rewrite SQL or ORM code using joins, grouped lookups, or eager loading.
Why use it?
It helps find why database work is slow, including the N+1 problem: one query loads a list, then another query runs for every item in that list.

Skill for Claude CodeCodex

Part of the performance-deity plugin — 17 skills shipped together

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.

agentmods
npx agentmods add skills/v0idos/performance-deity/database-deity
Any agent
npx skills add v0idOS/performance-deity --skill database-deity
Clone the repo
git clone --depth 1 https://github.com/v0idOS/performance-deity

Made for: Claude Code, Codex.

Or install performance-deity, the plugin that ships this one along with the rest of its 17 skills.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 296 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00296
Opus 5 $0.00000 $0.00148
Sonnet 5 $0.00000 $0.00059
Haiku 4.5 $0.00000 $0.00030

Measured 2d ago against content hash 15643ee64efe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

database-deity 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 2d 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.

archive/database-deity/SKILL.md · 28 lines

What it actually says

Database Deity: The N+1 Slayer

Description

This skill optimizes database queries and ORM interactions, focusing on index usage, query planning, and eliminating the N+1 query problem.

Triggers

Activate when the user mentions:

  • "slow query", "SQL"
  • "database optimization", "ORM"
  • "N+1"
  • Or explicitly runs /plugin performance-deity:database

Core Directives

Phase 1: Explain & Analyze

  1. Take the user's slow query or ORM logic.
  2. Generate the raw SQL.
  3. Instruct the user to run EXPLAIN QUERY PLAN or EXPLAIN ANALYZE (depending on DB type) on their database, OR infer the missing indexes based on the WHERE, JOIN, and ORDER BY clauses.

Phase 2: The N+1 Audit

  1. Check if the code is running queries inside a loop.
  2. If yes, rewrite the logic to use IN (...) clauses, SQL JOINs, or ORM eager loading (e.g., .include(), .populate(), select_related).

Phase 3: The Rewrite

  1. Provide the optimized SQL or ORM code.
  2. Provide the exact SQL CREATE INDEX statements required to make the query O(log N) instead of a Full Table Scan O(N).
  3. Explain the theoretical reduction in disk I/O.
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.

  1. 2d ago First seen · 28 lines · 0 tokens per session scan A 15643ee64efe

Subscribe to this mod's changes

database-deity is a skill published in the GitHub repository v0idOS/performance-deity (2 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 296 tokens. 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 2026-08-31.

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