altinity-expert-clickhouse-memory

Original：🇺🇸 English

Translated

Diagnose ClickHouse RAM usage, OOM errors, memory pressure, and allocation patterns. Use for memory-related issues and out-of-memory errors.

3installs

Added on2026-02-17

NPX Install

npx skill4agent add altinity/skills altinity-expert-clickhouse-memory

Diagnose RAM usage, memory pressure, OOM risks, and memory allocation patterns.

Run all queries from the file checks.sql and analyze the results.

Solutions:

Solutions:

sql

-- Always time-bound log queries
where event_date >= today() - 1

-- Limit results
limit 100

Finding	Load Module	Reason
High merge memory	`altinity-expert-clickhouse-merges`	Analyze merge patterns
Large dictionaries	`altinity-expert-clickhouse-dictionaries`	Dictionary optimization
Cache too large	`altinity-expert-clickhouse-caches`	Cache sizing
PK memory high	`altinity-expert-clickhouse-schema`	ORDER BY optimization
Query OOMs	`altinity-expert-clickhouse-reporting`	Query optimization

Setting	Scope	Notes
`max_memory_usage`	Query	Per-query limit
`max_memory_usage_for_user`	User	Per-user aggregate
`max_server_memory_usage`	Server	Global limit
`max_server_memory_usage_to_ram_ratio`	Server	Auto-limit as % of RAM
`max_bytes_before_external_group_by`	Query	Spill aggregation to disk
`max_bytes_in_join`	Query	Spill join to disk