The CoalescingMergeTree table engine

Mark Needham

The ClickHouse Merge Tree family just got a new member, and it's pretty exciting! In this video, we dive into the Coalescing Merge Tree engine, a fresh addition designed to handle partial row updates efficiently. If you've ever wanted to keep only the most up-to-date and complete version of each entity in your data, without the overhead of full row overwrites, this engine might be what you're looking for.

We'll walk you through:

• How the Coalescing Merge Tree engine works and when to use it
• A practical example using electric car telemetry data
• Creating and querying a Coalescing Merge Tree table in ClickHouse
• Comparing query results before and after merges
• Tips for optimizing your data storage and retrieval

This video is for you if you're dealing with IoT data, user profiles, or any scenario where you need to update and consolidate partial information efficiently.

• Blog - https://clickhouse.com/blog/clickhouse-25-6-coalescingmergetree