Create collections

The question to ask when you want to create a new collection is as follows:

Need you to access this information in the first collection?

If yes, you shouldn't create a new collection to store these informations.

The other reason we will be forced to separate these informations would come from the constraints of the maximum size of a document which can not exceed 16MB.

Except these two cases, you should create a new collection to store your informations.