MongoEngine is managing the connection globally (i.e once connected, it auto-magically re-use that connection), usually you call connect just once, when the application/script starts and then you are good to go, and don't need to interfere with the connection.
LazyReferenceField is not different from any other field (ReferenceField, StringField, etc) in that context. The only difference is that it's not doing the de-referencing immediatly but only when you explicitly request it with the .fetch method
I have documents in different MongoDB databases referencing each other (mongoengine's LazyRefereneceField), so each time I need to get the field's value, I need to connect and disconnect from the field's relevant database, which I find very inefficient.
I've read about connection pooling, but I can't find a solution on how to implement it using MongoEngine. How can I create a connection pool and reuse connections from it every time I need to the value for a LazyReferenceField?
Use connection pool with MongoEngine