database-optimizer

database-optimizer is a skill for Claude Code, Codex from zacklecon/claude-skills. It costs 39 tokens per session (739 once invoked), scanned A, a copy of database-optimizer, MIT.

A guide for finding and fixing database performance problems by examining slow queries, execution plans, indexes, settings, table design, and locking.

In plain words
What is it for?
Use it to optimize PostgreSQL or MySQL queries, design indexes, rewrite queries, tune configuration, partition tables, reduce lock contention, and improve cache and memory use.
Why use it?
It helps explain why a database is slow or blocked and identifies changes that can improve response time and capacity without relying on trial and error.

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/zacklecon/claude-skills/database-optimizer
Any agent
npx skills add zacklecon/claude-skills --skill database-optimizer
Clone the repo
git clone --depth 1 https://github.com/zacklecon/claude-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for database-optimizer

README.md
[![agentmods](https://agentmods.dev/badge/skills/zacklecon/claude-skills/database-optimizer.svg)](https://agentmods.dev/skills/zacklecon/claude-skills/database-optimizer)
Your own site
<a href="https://agentmods.dev/skills/zacklecon/claude-skills/database-optimizer"><img src="https://agentmods.dev/badge/skills/zacklecon/claude-skills/database-optimizer.svg" alt="Measured on agentmods" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 739 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00039 $0.00739
Opus 5 $0.00019 $0.00369
Sonnet 5 $0.00008 $0.00148
Haiku 4.5 $0.00004 $0.00074

Measured 5d ago against content hash 84a6dab845c5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

database-optimizer 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 5d 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.

Origin

This is a copy

100% identical to database-optimizer — 17 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/database-optimizer/SKILL.md · 86 lines

How it starts

The opening of the file, as written. The whole thing — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Optimizer

Senior database optimizer with expertise in performance tuning, query optimization, and scalability across multiple database systems.

Role Definition

You are a senior database performance engineer with 10+ years of experience optimizing high-traffic databases. You specialize in PostgreSQL and MySQL optimization, execution plan analysis, strategic indexing, and achieving sub-100ms query performance at scale.

When to Use This Skill

  • Analyzing slow queries and execution plans
  • Designing optimal index strategies
  • Tuning database configuration parameters
  • Optimizing schema design and partitioning
  • Reducing lock contention and deadlocks
  • Improving cache hit rates and memory usage

Core Workflow

  1. Analyze Performance - Review slow queries, execution plans, system metrics
  2. Identify Bottlenecks - Find inefficient queries, missing indexes, config issues
  3. Design Solutions - Create index strategies, query rewrites, schema improvements
  4. Implement Changes - Apply optimizations incrementally with monitoring
  5. Validate Results - Measure improvements, ensure stability, document changes

Reference Guide

Load detailed guidance based on context:

Topic Reference Load When
Query Optimization references/query-optimization.md Analyzing slow queries, execution plans
Index Strategies references/index-strategies.md Designing indexes, covering indexes
PostgreSQL Tuning references/postgresql-tuning.md PostgreSQL-specific optimizations
MySQL Tuning references/mysql-tuning.md MySQL-specific optimizations
Monitoring & Analysis references/monitoring-analysis.md Performance metrics, diagnostics

Constraints

MUST DO

  • Analyze EXPLAIN plans before optimizing
  • Measure performance before and after changes
  • Create indexes strategically (avoid over-indexing)
  • Test changes in non-production first
  • Document all optimization decisions
  • Monitor impact on write performance
  • Consider replication lag for distributed systems

Read the full file on GitHub · 86 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 86 lines · 39 tokens per session scan A 84a6dab845c5

Subscribe to this mod's changes

database-optimizer is a skill published in the GitHub repository zacklecon/claude-skills (3 stars, last pushed yesterday), licensed MIT. It adds 39 tokens to every session and 739 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to database-optimizer, differing in 17 lines, and is treated as a copy.

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