Nesting Stars In Firebase Database

I find Firebase Database sample very helpful, but I noticed something which worries me a little bit. I mean in this example user can give star to the post, something like 'Like it'

Solution 1:

firebaser here

When writing the examples for our documentation, we always have to balance the need for having enough context, keeping the example small enough , and following our own best practices.

This is indeed one of the cases where we violate one of our own best practices "not nesting data". As you said: this means that a user downloading a post, gets all the UIDs of users that liked that post.

As the usage of the application scales, that may become a concern. If that is the case for your app, you should model the "users who upvoted a post" as a separate top-level node:

"posts": {
    "post_id" : {
       "author": "username",
       "body": "Some content",
       "starCount": 1
      "title": "Some title",
      "uid": "author_id"
    }
},
"upvotes": {
    "post_id" : {
        "user_id_who_gave_star" : "true"
    }
}