This post has two documents with the same name ("jaeschke2008discovering_oa.pdf") attached. This should never have happened (TODO: ensure that this never happens again). Unfortunately, now I can neither rename nor delete (one of) the posts(s).
If that's an issue on the database level, a duplicate key constraint is probably missing (it might be that it's not feasible, since we use the table also for other things like the JabRef layouts where duplicate file names might be allowed?). If this can not be handled by a constraint (which would be preferable), checking for a duplicate name and storing the change needs to be done in a transaction.