Core concepts

Learn Core Concepts of how ClickHouse works

In this section of the documentation, you will learn some of the core concepts of how ClickHouse works.

Glossary

Commonly used ClickHouse words and phrases, and their definitions.

Table parts

Learn what table parts are in ClickHouse.

Table partitions

Learn what table partitions are and what they’re used for.

Table part merges

Learn what table part merges are and what they’re used for.

Primary indexes

How ClickHouse’s sparse primary index helps efficiently skip unnecessary data during query execution.

Query parallelism

How ClickHouse parallelizes query execution using processing lanes and the max_threads setting.

Architectural Overview

A concise academic overview of all components of the ClickHouse architecture, based on our VLDB 2024 scientific paper.