apology for my question, affects this also the table oc_filecache_extended or only oc_filecache? finally, the name is similar.
As you can see here: https://docs.nextcloud.com/server/19/admin_manual/configuration_server/occ_command.html#file-operations-label
occ files:cleanup allready makes the cleanup. And after that:
occ files:scan --all makes the rescan for all users.
I think the direct operation on the database layer is risky, and under the circumstance that there is a cleanup command at least strange. Possible there is a bug and have to be reported?
bye.