In the database world it is generally recognized that doing data duplication to 'flatten' a particular view is a special case of normalization (adapting data to a model) which is encouraged to be done dynamically (eg. as an SQL view) and not in stored data (as this would create redundant information, which negatively affects the database in terms of ongoing management, authority and clarity). Generating reports in whatever format users prefer is generally a very cheap and fast operation.

Also, duplicating the data does not make it more correct or more authoritative. Do not confuse presentation with data. A rose by any other name would smell as sweet.

Edit: I can't reply to your response so will reply here. I suggest reading some basic database design books. Good luck.