I am interested in how a large area 3D environment in games like Grand Theft Auto V or Far Cry can be stored (on disk, in what file format) and how that data can be retrieved when it is used in a game. By "the environment" I mean only static objects like terrain with vegetation, city areas with buildings, et cetera. I'm not referring to temporary or moving objects like people or cars. I am not interested in scene rendering.
I guess it may be convenient to shard (horizontally partition) the data by location creating something like "tiles" because it is usually accessed by location and such tiling will help to keep data that is related together (and reads will be faster). Also I guess the data for sure is stored in some (compressed?) 3D format with the respect to tiling. There probably have to be mechanisms that will split one object to two (or more) parts if it does not fit into a single tile.
I have found a somewhat related question (How a 3D game map is stored and handled) but it only briefly answers small part of my question.