As I understand it, you can copyright a database of facts based on the principle of “sweat of the brow”. So if someone was to create a list of everyone involved in the Seven Years War, their year of birth and death date then these are all facts AND out of copyright. The data could be stored in Excel (ie not a clever structure) and could be copyrightable because of the effort of compiling the list. I made this up but you can imagine someone devoting a lifetime to putting this list together.
Obviously the facts in the database in isolation are still not copyright. And you cannot steal someone elses work add two extra lines and say its yours …. or can you? See below.
My knowledge of this comes dealing with Wikim/pedia pictures. The National Portrait Gallery claim that the “sweat of the brow” of taking a 300 year old painting and taking a photo of it means they can claim a copyright on the derived picture. Wikim/pedia don’t agree as the effort is so small ….. there is no “sweat”. The NPG have been litigous about this in the past …. but not pressed home their opinion. So it depends on the amount of sweat. Anti-perspirant? anyone.