It’s a combination of “Clickstream” and “Data wareHouse”. It comes from the original use case at Yandex.Metrica, where ClickHouse was supposed to keep records of all clicks by people from all over the Internet and it still does the job. You can read more about this use case on ClickHouse history page.
This two-part meaning has two consequences:
- The only correct way to write ClickHouse is with capital H.
- If you need to abbreviate it, use CH. For some historical reasons, abbreviating as CK is also popular in China, mostly because one of the first talks about ClickHouse in Chinese used this form.
Many years after ClickHouse got its name, this approach of combining two words that are meaningful on their own has been highlighted as the best way to name a database in a research by Andy Pavlo, an Associate Professor of Databases at Carnegie Mellon University. ClickHouse shared his “best database name of all time” award with Postgres.