Database structure for linkedin like user connection

Working with Data Drivers
1

Hello,

I want to design the db structure for something link linkedin user connection. Now the data can be really big. I made once db with collection called user_connection

id_
user_m_id (String),
user_c_id (String),
is_approved (bool),
rel_type (family, buddy, mentor)
rel_type_id (String)
entry_date_time(datetime),
last_update_date_time(datetime)

Now have two 2 question as below:

  1. Will it be good to keep all data in one collection - If no then how to separate
  2. Can graph database like neptune or neo4j will work on top of mongo db to fetch data for recommendation of 1st, 2nd, 3rd connection

Thanks in advance