How to load huge data in firebase recyclerview efficiently

Question

There is something more than 6000 entries in child mDatabase

    mDatabase = FirebaseDatabase.getInstance().getReference().child("CurrentQuizResult");

    Query query = mDatabase.orderByChild("score");

    final FirebaseRecyclerAdapter<BlogScore, AffairsHigh.BlogScoreViewHolder> FirebaseRecyclerAdapter = new FirebaseRecyclerAdapter
            <BlogScore, AffairsHigh.BlogScoreViewHolder>(BlogScore.class, R.layout.blogscore, AffairsHigh.BlogScoreViewHolder.class, query) {


        @Override
        protected void populateViewHolder(final AffairsHigh.BlogScoreViewHolder viewHolder, BlogScore model, final int position) {




            final String post_key = getRef(position).getKey();

            
            });
            viewHolder.setDesc(model.getDesc());
            viewHolder.setUserimage(getApplicationContext(), model.getUserimage());
            viewHolder.setUsername(model.getUsername(),post_key,getApplicationContext());
        }


    };


    mBlogList.setAdapter(FirebaseRecyclerAdapter);

But in this code, it is downloading all 6000 nodes in mDatabase child which are consuming high database usage. Here how I can load data whose score is greater than 200 so that in Query it doesn't load useless data which not required. Any solution for that using Query in firebase??

Answer 1

To only load the data where the score is larger than 200, you can do:

Query query = mDatabase.orderByChild("score").startAt(200);

For more on this, see the Firebase documentation on filtering data .

---

If the app is still downloading all data, even when you add a filter, you may not have added a server-side index in your database's security rules.

For the query you run, you need to have this index in your rules:

{
  "rules": {
    "CurrentQuizResult": {
      ".indexOn": "score"
    }
  }
}