In our previous post, we reviewed the SQL JOIN types that are available in ClickHouse. As a reminder: ClickHouse comes with full SQL Join Support.

In this post, we’ll explore the internals of join execution in ClickHouse, so that you can optimize joins for queries used by your applications. Here, you’ll see how ClickHouse integrates these classical join algorithms into its query pipeline in order to execute the join types as fast as possible.