altinity Storage and Disk Usage Analysis
Diagnose disk usage, compression efficiency, part sizes, and storage bottlenecks.
Diagnostics
Run all queries from checks.sql in this skill's directory and analyze the results.
Ad-Hoc Query Guidelines
Required Safeguards
-- Always limit results
limit 100
-- For part_log
where event_date >= today() - 1
Key Tables
system.disks- Disk configurationsystem.parts- Part storage detailssystem.columns- Column compressionsystem.storage_policies- Tiered storagesystem.detached_parts- Orphaned parts
Cross-Module Triggers
| Finding | Load Module | Reason |
|---|---|---|
| Poor compression | altinity-expert-clickhouse-schema |
Codec recommendations |
| Many small parts | altinity-expert-clickhouse-merges |
Merge backlog |
| High write IO | altinity-expert-clickhouse-ingestion |
Batch sizing |
| System logs large | altinity-expert-clickhouse-logs |
TTL configuration |
| Slow disk + merges | altinity-expert-clickhouse-merges |
Merge optimization |
Settings Reference
| Setting | Notes |
|---|---|
min_bytes_for_wide_part |
Threshold for Wide vs Compact parts |
min_rows_for_wide_part |
Row threshold for Wide parts |
max_bytes_to_merge_at_max_space_in_pool |
Max merge size |
prefer_not_to_merge |
Disable merges (emergency) |