# ClickHouse vs Prometheus for High Cardinality, Part 2: Cardinality in ClickHouse

DevFeed: [ClickHouse vs Prometheus for High Cardinality, Part 2: Cardinality in ClickHouse](<https://devfeed.tech/articles/clickhouse-vs-prometheus-for-high-cardinality-part-2-cardinality-in-clickhouse-5160.md>)

Original publisher: [Read original article](<https://clickhouse.com/blog/clickhouse-vs-promethous-high-cardinality-part-2-cardinality-in-clickhouse>)

Author: Rory Crispin; Dale McDiarmid

Published: 2026-05-15T00:00:00Z

Content type: article

Language: en

Sources: [ClickHouse Blog](<https://devfeed.tech/sources/clickhouse-blog.md>)

Topics: [clickhouse](<https://devfeed.tech/topics/clickhouse.md>), [Prometheus](<https://devfeed.tech/topics/prometheus.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [telemetry](<https://devfeed.tech/topics/telemetry.md>), [Temporal data](<https://devfeed.tech/topics/temporal-data.md>), [data](<https://devfeed.tech/topics/data.md>), [systems](<https://devfeed.tech/topics/systems.md>)

Tags: [clickhouse](<https://devfeed.tech/tags/clickhouse.md>), [data](<https://devfeed.tech/tags/data.md>), [databases](<https://devfeed.tech/tags/databases.md>), [logs](<https://devfeed.tech/tags/logs.md>), [metrics](<https://devfeed.tech/tags/metrics.md>), [observability](<https://devfeed.tech/tags/observability.md>), [prometheus](<https://devfeed.tech/tags/prometheus.md>), [systems](<https://devfeed.tech/tags/systems.md>), [telemetry](<https://devfeed.tech/tags/telemetry.md>), [time-series](<https://devfeed.tech/tags/time-series.md>)

## AI overview

This article examines how ClickHouse and other column-oriented databases handle high-cardinality observability data differently from Prometheus and other series-oriented time-series databases. It explains that ClickHouse shifts much of the cost from ingestion to query time and models telemetry as wide, timestamped events with dimensions, attributes, and measurements that can be aggregated later. The article also notes that ClickHouse is not a drop-in replacement for Prometheus and requires a different approach to telemetry, instrumentation, and aggregation.

## Source excerpt

In this blog, we explore why high cardinality behaves fundamentally differently in column-oriented databases like ClickHouse, and why the costs appear in very different places than in traditional series-based systems like Prometheus.