In an app, there are certain data that are crucial, for example, transactions or consultations that has a long history.
Should a user be able to delete this record permanently and just provide a confirmation before deletion?
Or should we prevent them from deleting certain data and instead, maybe, contact the administrator to delete for them?
I think you should not permanently delete those data since you have mentioned it crucial (I think you mean crucial to the user here.) for example I don't want to delete my order history in amazon for any reason, since I always want to come back and see my order history any time I want. If user insists for that then you can show a confirmation say:
You have decided to delete this info and this will be moved to deleted history section
then move deleted information to say some deleted history tab or a section this is just an example, which can be changed according to the use-case.
the point here is most of the time user don't want any of his information to be lost, especially those which are generated by your app. hope this helps.
If the user wants his data deleted you have to do so (if we are talking about user information/content and there is no obligation from a legal point of view for you to keep that data). These are two ways that could be combined:
Trash: An approach is to send this to a trash that will be deleted with a second delete confirmation from there.
Time delay: Letting the user know his data will be deleted in a certain time, a week for example, in case he realises he wants it back. Until that time the data is not visible for him.
