clickhouse-js
Installation
SKILL.md
ClickHouse Schema & Query Conventions
Apply these conventions when working with ClickHouse databases.
Engine Selection
| Use Case | Engine | Notes |
|---|---|---|
| General analytics | MergeTree |
Default choice |
| Deduplicate by key | ReplacingMergeTree(ver) |
Use FINAL or GROUP BY in queries for correctness |
| Pre-aggregate sums | SummingMergeTree |
Auto-sums numeric cols on merge |
| Custom aggregations | AggregatingMergeTree |
With AggregateFunction columns + -State/-Merge |
| Mutable data (ordered inserts) | CollapsingMergeTree(sign) |
sign=+1 insert, sign=-1 cancel |
| Mutable data (any order) | VersionedCollapsingMergeTree(sign, ver) |
Safe with concurrent inserts |