As I mentioned, there's only 1 place where it says anything about fsync, and in that page, it says that is only for creating .sql files. https://groups.google.

As I mentioned, there's only 1 place where it says anything about fsync, and in that page, it says that is only for creating .sql files. https://groups.google.com/d/msg/clickhouse/cjJ6v8uzu0Q/jGV59S0VBQAJ https://groups.google.com/d/msg/clickhouse/cjJ6v8uzu0Q/jGV59... > The reason is because CH does not use fsync (for performance) https://www.linkedin.com/in/dzhuravlev/ https://www.linkedin.com/in/dzhuravlev/