These settings are available in system.merge_tree_settings and are autogenerated from the ClickHouse snapshot.
refresh_parts_interval
If it is greater than zero - refresh the list of data parts from the underlying filesystem to check if the data was updated under the hood. It can be set only if the table is located on readonly disks (which means that this is a readonly replica, while data is being written by another replica).
refresh_statistics_interval
The interval of refreshing statistics cache in seconds. If it is set to zero, the refreshing will be disabled.