Technology

ClickHouse

Summary

What it is

A column-oriented DBMS designed for real-time analytical queries, with native support for reading from and writing to S3.

Where it fits

ClickHouse occupies the performance tier above pure lakehouse queries. It can use S3 as a storage backend (S3-backed MergeTree) while maintaining its own columnar indexes for sub-second query performance — bridging the gap between S3 data lakes and dedicated analytics databases.

Misconceptions / Traps

  • ClickHouse with S3 storage is not the same as querying S3 directly. ClickHouse maintains local indexes and metadata for performance; it uses S3 for durability and cost.
  • The S3 table function (for ad-hoc S3 reads) and the S3-backed MergeTree engine (for persistent tables) are different features with different performance characteristics.

Key Connections

  • depends_on Apache Parquet — reads/writes Parquet for S3 interop
  • implements Separation of Storage and Compute — S3-backed storage with independent compute
  • scoped_to S3, Lakehouse

Definition

What it is

A column-oriented database management system designed for real-time analytical queries, with native support for reading from and writing to S3.

Why it exists

Some analytical workloads require sub-second query performance on recent data, which pure S3-backed query engines cannot consistently deliver. ClickHouse uses S3 as a storage backend while maintaining its own columnar indexes for speed.

Primary use cases

Real-time analytics dashboards backed by S3 storage, log analytics with S3 archival, hybrid hot/cold query patterns.

Relationships

Outbound Relationships

scoped_to
S3Lakehouse
depends_on
Apache Parquet
implements
Separation of Storage and Compute

Inbound Relationships

used_by
Apache Parquet

Resources

DocsHigh
clickhouse.com/docs

Official ClickHouse documentation covering the column-oriented OLAP database engine, SQL dialect, and all table engines.

GitHubHigh
github.com/ClickHouse/ClickHouse

The primary ClickHouse repository — one of the most active C++ database projects, with the full analytical engine source.

DocsHigh
clickhouse.com/docs/en/integrations/s3

ClickHouse's dedicated S3 integration page documents the S3 table function, S3Queue engine, S3-backed MergeTree, and S3 disk configuration.

ChangelogHigh
clickhouse.com/docs/en/whats-new/changelog

Detailed ClickHouse changelog tracks every release including S3 engine improvements and storage backend changes.