#clickhouse
[[clickhouse]] ![[Screenshot 2023-02-14 at 20.23.20.png]]
Clickhouse inserts data ASAP, and merge the files in the background.
When you INSERT a bunch of data into MergeTree, that bunch is sorted by primary key order and forms a new part. There are background threads that periodically select some parts and merge them into a single sorted part to keep the number of parts relatively low. That’s why it is called MergeTree.