clickhouse-best-practices

A set of 28 validated rules for ClickHouse covering schema design, query optimization, and data ingestion. Rules are grouped by category and priority, from primary key selection to mutation avoidance. Meant to be checked against before answering ClickHouse questions or reviewing database code. ClickHouse has specific behaviors around columnar storage and sparse indexes where standard SQL intuition leads to bad designs, and these rules encode validated ClickHouse-specific guidance that general database knowledge won't cover.