actually, google docs ARE append only. They use the vaunted google wave tech of Operational Transforms. every single timestamped keystroke is saved separately i

actually, google docs ARE append only. They use the vaunted google wave tech of Operational Transforms. every single timestamped keystroke is saved separately in the database. when two users are involved, and editing simultaneously, the OT algorithms resolve the merge conflict on the spot. it kind of looks like a tree structure, or an append only array. the actual document you are looking it is actually something like a flattened keyframe in a movie that's reached the end.