ClickHouse Performance Tuning

Overview

Diagnose and fix ClickHouse performance issues using query analysis, proper indexing, projections, materialized views, and server settings tuning. Work top-down: measure first with system.query_log, then apply the single highest-leverage fix (usually the ORDER BY key), then re-measure to confirm.

Prerequisites

• ClickHouse tables with data (see clickhouse-core-workflow-a)
• Access to system.query_log and system.parts

Instructions

The tuning workflow is seven independent steps. Diagnose first, then reach for the fix that matches the bottleneck. Each step's full SQL lives in references/implementation.md — start there for the complete, copy-paste commands.