ClickHouse Common Errors

Overview

Quick reference for the most common ClickHouse errors with real error codes, diagnostic queries, and proven solutions. The three highest-frequency errors are inline below; the full catalog of 10 errors plus system-table diagnostics lives in references/error-reference.md.

Prerequisites

• Access to a ClickHouse endpoint — either the native clickhouse-client or the HTTP interface (curl against :8123).
• Permission to read the system.* introspection tables (system.parts, system.processes, system.query_log, system.columns, system.replicas).
• The failing statement's text and, ideally, the raw exception string — the parenthetical name (e.g. MEMORY_LIMIT_EXCEEDED) and numeric code drive lookup.

Instructions