"Periodically readd file entries of internet clients to database"

Server
1

8.9 Periodically readd file entries of internet clients to database

If checked UrBackup will periodically refresh hashes in its database such that backup deletions do not cause UrBackup to re-download files that are already present in the backup storage.

I struggle to understand the purpose of this feature. Can someone provide a use-case for demonstration?

2

I disabled this option, and noticed from the backup log that existing files are still being readded, and then the log says:

34.1286 MB of files were already present on the server and did not need to be transferred

What’s going on here?