ClickHouse Upgrade & Migration

Overview

Safely upgrade ClickHouse server and the @clickhouse/client Node.js SDK, with rollback procedures and breaking-change detection. The workflow is check versions → review changelogs → upgrade the client → upgrade the server → validate → rollback if needed. Full command sequences live in references/implementation.md; the runnable migration, validation, and rollback code lives in references/examples.md.

Prerequisites

• Current ClickHouse version known (SELECT version())
• Git for version control (client changes land on an upgrade/ branch)
• Test suite for integration validation (npm test)
• Staging environment for pre-production testing
• CLICKHOUSE_HOST set (and credentials — see Authentication)