The text discusses the evolution of SQL-style UPDATE operations in ClickHouse, a columnar database, which traditionally faced challenges in efficiently handling updates due to its architecture prioritizing read speed over write operations. Initially, ClickHouse employed a mutation model that was reliable but heavy on resources, involving full-column rewrites and delayed visibility of changes. To address these limitations, ClickHouse introduced on-the-fly updates for immediate visibility and later developed "patch parts," a novel mechanism allowing lightweight, efficient updates by treating updates as inserts. Patch parts apply changes during background merges, leveraging the existing high-speed insert and merge capabilities of ClickHouse, ensuring minimal overhead and instant visibility of updates. This approach not only maintains the database's performance but also integrates seamlessly with SQL syntax, providing users with the ability to perform updates without sacrificing speed or scalability. The improved update mechanisms significantly outperform traditional methods, with benchmarks showing up to a 1,000× increase in speed, marking a substantial advancement in handling updates within columnar storage systems.