Does ClickHouse Support UPDATEs? A 2026 Data Analysis

TL;DR Yes, ClickHouse fully supports UPDATEs. As of April 2026, ClickHouse ships standard SQL UPDATE ... SET ... WHERE syntax that runs in milliseconds, alongside four other update mechanisms: ALTER TABLE … UPDATE mutations for bulk operations, lightweight DELETE, on-the-fly mutation visibility, and ReplacingMergeTree for high-volume upserts and CDC. The "ClickHouse is append-only" claim is outdated by eight years and 100+ merged pull requests. Key facts: Standard SQL UPDATE shipped in ClickHous