I know it is said that BigDb is a NoSQL database an so is "schema-less", but for my game there is a standard way for structured each players PlayerObject so that it is standardized and can be read by the code. So suppose we have a simple PlayerObject structure with the player's name as the key. Then inside there is an object called "stats" with one integer, "wins".
Now suppose we release the game and people are playing it, registering accounts, etc. In the register method we create all the player's PlayerObjects as described above. However, now the CEO (or whoever) comes along and says we need a new parameter in the stats object, "losses". It's simple to change the register method so that all new users have their PlayerObject like this, but what about all the users that have already been created?
So that is my question. How do you update all of the users at once? Something like, "select all users and add this integer property in the stats object"?