Single collection with a key vs multiple collections I am designing the DB for a project, where, I am sure that I would not be querying for data belonging to multiple values of a key x at the same time.  All queries will be for sure for a given value of x.  Is it better to create a single collection having an index for x, or is it better to create multiple collections having x as part of the collection name?

I want to optimize storage space, and well as ensure reasonable read query performance.
Answer is single collection at this case.