altinity-expert-clickhouse-caches

altinity-expert-clickhouse-caches is a skill for Claude Code, Codex from Altinity/altinity-skills. It costs 36 tokens per session (484 once invoked), scanned A, original, Apache-2.0.

A ClickHouse cache-analysis skill examines the database's mark, uncompressed, query, and compiled-expression caches. ClickHouse is a database designed for analytical queries over large datasets.

In plain words
What is it for?
It is for diagnosing cache behavior and recommending cache sizes or related ClickHouse tuning changes.
Why use it?
It helps explain poor cache hit rates, excessive memory use, and disk input/output when queries run.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It is for diagnosing cache behavior and recommending cache sizes or related ClickHouse tuning changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/altinity/altinity-skills/altinity-expert-clickhouse-caches
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.

Any agent
npx skills add Altinity/altinity-skills --skill altinity-expert-clickhouse-caches
Clone the repo
git clone --depth 1 https://github.com/Altinity/altinity-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 altinity-expert-clickhouse-caches

README.md
[![agentmods](https://agentmods.dev/badge/skills/altinity/altinity-skills/altinity-expert-clickhouse-caches/github.svg)](https://agentmods.dev/skills/altinity/altinity-skills/altinity-expert-clickhouse-caches)
Your own site
<a href="https://agentmods.dev/skills/altinity/altinity-skills/altinity-expert-clickhouse-caches"><img src="https://agentmods.dev/badge/skills/altinity/altinity-skills/altinity-expert-clickhouse-caches/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.

agentmods 80×15 button for altinity-expert-clickhouse-caches

Your own site · 80×15
<a href="https://agentmods.dev/skills/altinity/altinity-skills/altinity-expert-clickhouse-caches"><img src="https://agentmods.dev/badge/skills/altinity/altinity-skills/altinity-expert-clickhouse-caches.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 484 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00036 $0.00484
Opus 5 $0.00018 $0.00242
Sonnet 5 $0.00007 $0.00097
Haiku 4.5 $0.00004 $0.00048

Measured 10d ago against content hash fdb70e648c45, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

altinity-expert-clickhouse-caches 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 10d 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.

altinity-expert-clickhouse/skills/altinity-expert-clickhouse-caches/SKILL.md · 70 lines

What it actually says

Cache Analysis and Tuning

Analyze ClickHouse cache systems: mark cache, uncompressed cache, query cache, and compiled expression cache.


Diagnostics

Run all queries from checks.sql in this skill's directory and analyze the results.


Cache Sizing Recommendations

Cache Typical Size Notes
Mark Cache 5-10% of RAM Higher if random access patterns
Uncompressed 0 (disabled) or 5-10% Enable only for specific workloads
Query Cache 1-5GB For repeated identical queries
Compiled Expression 128MB-1GB Higher for complex expressions

Problem Investigation

Poor Mark Cache Hit Ratio

Possible causes:

  1. Cache too small for working set
  2. Queries scan many different tables
  3. Many small queries to cold data

Cache Too Large

If mark cache > 15% RAM:

Solutions:

  • Reduce index_granularity for tables with excessive marks
  • Drop unused tables
  • Reduce mark_cache_size setting

Cross-Module Triggers

Finding Load Module Reason
Cache using too much RAM altinity-expert-clickhouse-memory Overall memory analysis
Poor hit ratio + high disk IO altinity-expert-clickhouse-storage Disk bottleneck
Many marks per table altinity-expert-clickhouse-schema Consider index_granularity tuning
Query cache misses altinity-expert-clickhouse-reporting Query pattern analysis

Settings Reference

Setting Scope Notes
mark_cache_size Server Global mark cache limit
uncompressed_cache_size Server Set to 0 to disable
use_uncompressed_cache Query Enable per-query
query_cache_max_size Server Query result cache
use_query_cache Query Enable per-query
Files

What ships with it

1 file 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. 10d ago First seen · 70 lines · 36 tokens per session scan A fdb70e648c45

Subscribe to this mod's changes

altinity-expert-clickhouse-caches is a skill published in the GitHub repository Altinity/altinity-skills (16 stars, last pushed yesterday), licensed Apache-2.0. It adds 36 tokens to every session and 484 once invoked, about $0.0002 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.