discover-database

A skill finder for databases, systems that store and retrieve application data. It covers SQL and NoSQL databases, schemas, queries, migrations, connections, ORMs, caching, and database choice.

In plain words
What is it for?
Use it when designing schemas, optimizing SQL queries, planning migrations, modeling MongoDB documents, configuring Redis or connection pools, choosing a database, or adding caching.
Why use it?
It reduces the need to search separately for advice on storing data, changing schemas, improving queries, and handling connections. Relevant database guidance is found automatically.

Skill for Claude CodeCodex

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/rand/cc-polymath/discover-database
Any agent
npx skills add rand/cc-polymath --skill discover-database
Clone the repo
git clone --depth 1 https://github.com/rand/cc-polymath

Made for: Claude Code, Codex.

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,830 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 $0.00052 $0.01830
Opus 5 $0.00026 $0.00915
Sonnet 5 $0.00010 $0.00366
Haiku 4.5 $0.00005 $0.00183

Measured 2d ago against content hash e38b9e18cfab, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

discover-database 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.

skills/discover-database/SKILL.md · 260 lines

How it starts

The opening of the file, as written. The whole thing — 260 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Skills Discovery

Provides automatic access to comprehensive database design, optimization, and implementation skills.

When This Skill Activates

This skill auto-activates when you're working with:

  • SQL databases (PostgreSQL, MySQL)
  • NoSQL databases (MongoDB, Redis)
  • Database schema design and modeling
  • Query optimization and performance tuning
  • Database migrations and schema evolution
  • Connection pooling configuration
  • ORM usage and patterns
  • Database selection and architecture decisions
  • caching
  • cache
  • Redis
  • CDN
  • HTTP caching
  • cache invalidation
  • performance
  • Service Workers

Available Skills

Quick Reference

The Database category contains 19 skills across 2 subcategories:

Database (12 skills):

  1. postgres-schema-design - Schema design, relationships, data types, normalization
  2. postgres-query-optimization - EXPLAIN plans, indexes, slow query debugging
  3. postgres-migrations - Schema changes, zero-downtime, rollback strategies
  4. mongodb-document-design - Document modeling, embedding vs referencing
  5. redis-data-structures - Caching, sessions, rate limiting, leaderboards
  6. database-connection-pooling - Pool configuration, debugging exhaustion
  7. orm-patterns - ORM best practices, N+1 prevention, eager loading
  8. database-selection - Choosing databases, SQL vs NoSQL decisions

Plus 4 more in ../database/INDEX.md

Caching (7 skills): See ../caching/INDEX.md

Load Full Category Details

Read ../database/INDEX.md Read ../caching/INDEX.md

Common Workflows

New Database Project

Sequence: Selection → Schema design → Connection pooling

Read ../database/database-selection.md # Choose database Read ../database/postgres-schema-design.md # or mongodb-document-design.md Read ../database/database-connection-pooling.md

Query Performance Debugging

Sequence: Optimization → Connection pooling → ORM patterns

Read ../database/postgres-query-optimization.md # Debug slow queries Read ../database/database-connection-pooling.md # Check pool settings Read ../database/orm-patterns.md # Fix N+1 queries

Read the full file on GitHub · 260 lines

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 · 260 lines · 52 tokens per session scan A e38b9e18cfab

Subscribe to this mod's changes

discover-database is a skill published in the GitHub repository rand/cc-polymath (136 stars, last pushed 6mo ago), licensed MIT. It adds 52 tokens to every session and 1,830 once invoked, about $0.0003 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 2026-08-30.

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