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.
npx skills add HK-hub/AgentSkills --skill database-optimizergit clone --depth 1 https://github.com/HK-hub/AgentSkillsWrote 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.
[](https://agentmods.dev/skills/hk-hub/agentskills/database-optimizer)<a href="https://agentmods.dev/skills/hk-hub/agentskills/database-optimizer"><img src="https://agentmods.dev/badge/skills/hk-hub/agentskills/database-optimizer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/hk-hub/agentskills/database-optimizer"><img src="https://agentmods.dev/badge/skills/hk-hub/agentskills/database-optimizer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00054 | $0.01358 |
| Opus 5.5 | $0.00022 | $0.00543 |
| Sonnet 5.5 | $0.00011 | $0.00272 |
| Haiku 4.5 | $0.00005 | $0.00136 |
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 1mo 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.
This is a copy
100% identical to database-optimizer — 5 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.
How it starts
The opening of the file, as written. The whole thing — 148 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.
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
- Analyze Performance — Capture baseline metrics and run
EXPLAIN ANALYZEbefore any changes - Identify Bottlenecks — Find inefficient queries, missing indexes, config issues
- Design Solutions — Create index strategies, query rewrites, schema improvements
- Implement Changes — Apply optimizations incrementally with monitoring; validate each change before proceeding to the next
- Validate Results — Re-run
EXPLAIN ANALYZE, compare costs, measure wall-clock improvement, document changes
⚠️ Always test changes in non-production first. Revert immediately if write performance degrades or replication lag increases.
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 |
Common Operations & Examples
Identify Top Slow Queries (PostgreSQL)
-- Requires pg_stat_statements extension
SELECT query,
calls,
round(total_exec_time::numeric, 2) AS total_ms,
round(mean_exec_time::numeric, 2) AS mean_ms,
round(stddev_exec_time::numeric, 2) AS stddev_ms,
rows
FROM pg_stat_statements
ORDER BY mean_exec_time DESC
LIMIT 20;
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.
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.
- 1mo ago First seen · 148 lines · 54 tokens per session scan A 8741e33a0e57
database-optimizer is a skill published in the GitHub repository HK-hub/AgentSkills (6 stars, last pushed 2mo ago), licensed MIT. It adds 54 tokens to every session and 1,358 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to database-optimizer, differing in 5 lines, and is treated as a copy.
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