spring - Mongodb combine collections in java, and retrieve specific documents -

I am trying to combine two collections in the MongoDB in Java. The structure of my archive looks like this:

Global + - 100k Rows:

  _id | Registration | Type _________ | ______________________ | ____________ 018024 | 5 A-IAA A306  

Type + - 1000 rows:

  _id | Wake up Code | Manufacturer | _________ | _____________ | _______________________________ | __________________ | A306. H | A300B 4-600 / C4-600 / F4-600. Airbus |  

I have to insert it dynamically, so that I can update it. I am using a webcrawler system to retrieve this data, and so my program wants to be able to update it and retrieve it.

I'm looking at mongodb refs and embedded documents and in my structure while embedded will look like this:

  _id: 018024 Registration: 5A-IAE type: A306 { _id: A306 awake: H type: A-300B4-600 /. Producer: Airbus}  

My question is:

How can I get many such data in MongodiBee from multiple collections and how will I update it dynamically?

Thanks in advance for any input.