How do you track record relations in NoSQL?

Question

I am trying to figure out the equivalent of foreign keys and indexes in NoSQL KVP or Document databases. Since there are no pivotal tables (to add keys marking a relation be

Answer 1

Although, it is best to use RDBMS in such cases instead of NoSQL, yet one possible solution is to maintain additional nodes or collections to manage mapping and indexes. It may have additional cost in form of extra collections/nodes and processing, but it will give an solution easy to maintain and avoid data redundancy.