Manually finding and deleting orphaned files (M2.2+)

Hi all,

If this is not the right forum to ask the following questions, I kindly ask the forum moderators to move this post to a more appropriate forum.

I downloaded the Moodledata file and searched the folder for huge files. In phpMyAdmin I opened mdl_files, sorted them with largest file at the top and showing all files. Then I used the name of the largest file from Moodledata and didn't find it in mdl_files.

a) Is such a file called an "orphaned" file?

b) Can I manually delete such a file from Moodledata without corrupting the database?

With kind regards,

Hartmut