Use hash_of_all_files from system.parts for on-cluster backup identity checks

Why it matters

This feature enhances the integrity check during on-cluster backups by using a comprehensive hash of all files in a part to ensure that the parts are identical. It helps detect any inconsistencies or corruption in parts, improving the reliability of backup and restore operations.

How to use it

During on-cluster backup operations, ClickHouse will automatically use the hash_of_all_files from system.parts to verify parts identity. No additional user intervention is required to enable this feature.