I've been on Lemmy for some time now and it's time for me to finally understand how Federation works. I have general idea and I have accounts on three federated instances, but I need some details.
Let Alpha, Beta, Gamma and Delta be four federated instances. I have an account on Alpha and create a post in a community on Beta. A persoson from Gamma comments on it and a person from Delta upvotes the post and the comment.
The question: On which instances are the post, the comment and the upvotes stored?
Regardless of which on you create the content on, assuming they all federated with each other correctly, every instance hosts its own copy of your posts.
I used the term "normalized" in the context of databases. One piece of data should exists only once. But, this contradicts your points of redundancy and control.
That isn't what normalized means in the context of databases.
Also databases store the same data many times over often. For redundancy and load-balancing purposes. Really, federation just takes care of replication somewhat.
The only objection I have with that is redundancy is useless because if the main server who "host" the community goes down then all the other copies will die too as content can't be added anymore.