LowCardinality
LowCardinality is a ClickHouse optimization that dictionary-encodes column values, reducing storage and improving query performance for columns with many repeated values (fewer than ~10,000 unique values).
LowCardinality(String)
import { LowCardinality } from "@514labs/moose-lib"; interface Event { id: string; status: string & LowCardinality; // LowCardinality(String) country: string & LowCardinality; // LowCardinality(String) category: string & LowCardinality; // LowCardinality(String)}When to use LowCardinality
Use for columns with fewer than ~10,000 unique values that repeat frequently—status codes, country codes, categories, or log levels. Reduces storage and improves query performance.
See Also
- Strings — Standard string types
- Enums — Fixed set of categorical values
- ClickHouse LowCardinality — ClickHouse official documentation