Check that both tables have the same engine type, so there isn’t a mix of for example MyISAM and InnoDB.
When it is not possible to delete a file using rm even when logged in as root or by using sudo, check the file attributes with:
If it has the “i” attribute, this is preventing the file from being deleted, even by super users. When you have verified the reason for this and still want to delete the file then remove the “i” attribute with:
chattr -i filename.ext
Then delete the file using rm as you normally would.