Any user who must perform any form of update, delete, or insert operations, including the insert and update operations performed by a MERGE request, must be granted the SELECT privilege on all columns that are read by the delete, insert, merge, or update request from which that user must read values.
For the INSERT statement, SELECT privileges are required only if a table is to be reflexively grown by INSERT ... SELECT statements performed on itself.
Be careful when granting the delete privilege through a view, because data in columns that are not defined in the view (and which may be important to the enterprise) may accidentally be deleted by the user when deleting a row through a view.