Question DUMP_D content large despite no local backups

[Bitpalast]

In the Plesk backup directory DUMP_D I find these files and directories that total 385 GB although no local backups exist in the backup manager.

total 106632
drwxr-x---     5 psaadm psaadm    94208 Aug 10 06:37 .
drwxr-xr-x.    7 root   root       4096 Aug  9 09:37 ..
drwxr-x---  1674 root   root      69632 Jul  5 08:09 clients
drwxr-x---   707 root   root     360448 Aug 10 01:37 .discovered
drwxr-x---    12 root   root       4096 Feb 14 11:12 domains
-rw-r--r--     1 root   root       1100 Aug 10 04:01 .last-dumps
-rw-------     1 root   root   12096230 Aug 10 06:37 mysql.daily.dump.0.gz
-rw-------     1 root   root   12100863 Aug  9 09:26 mysql.daily.dump.1.gz
-rw-------     1 root   root   12119122 Aug  8 06:21 mysql.daily.dump.2.gz
-rw-------     1 root   root   12110894 Aug  7 06:51 mysql.daily.dump.3.gz
-rw-------     1 root   root   12107557 Aug  6 06:37 mysql.daily.dump.4.gz
-rw-------     1 root   root   12085090 Aug  5 06:44 mysql.daily.dump.5.gz
-rw-------     1 root   root   12066626 Aug  4 07:04 mysql.daily.dump.6.gz
-rw-------     1 root   root   12002743 Aug  3 06:58 mysql.daily.dump.7.gz
-rw-------     1 root   root   11945835 Aug  2 09:54 mysql.daily.dump.8.gz

Most of the data is included in clients and domains. Can these directories safely be deleted so that the next backup will still work as expected? Or do these need to remain in he DUMP_D directory for some reason, e.g. to calculate incremental backups correctly or in a timely manner?