CODEWITHSUNDEEP
androidperformancefirebasefirebase-realtime-database
Rahul
Rahul

Reputation: 372

Firebase Android: Which one is a better way to query in for selected node?

I'm developing a chat base app in Firebase Android. I got 2 ways to get the same result, but not able to detect which one is better in performance. Need help with following.

DB Structure:

Firebase - 
    - User
          - user id
                - name
                - DOB
                - userId

I need to fetch the user info for selected key. So there are 2 ways as follows:

  1. Create Firebase database reference until userId and add an event listener to it:

    database.child("Users").child(userCurrent.getUserId()).addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

    }

    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
});

  2. Create a Firebase database reference until Users node and then try to find the exact user by using equalTo query on key:

    database.child("Users").orderByKey().equalTo(userCurrent.getUserId()).addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

Will the second option fetch every user from User node and then query for equalTo?

Upvotes: 0

Views: 198

Answers (1)

Andrej Jurkin
Andrej Jurkin

Reputation: 2266

You don't need to query if you can create exact reference to your user object. Querying is totally unnecessary in this case and of course worse performance.

The second option will not fetch every user on the Users node, it will just perform a query and return the user you are looking for.

Also if you don't want to listen for every change on the node I suggest using the addListenerForSingleValueEvent(), which will read the value one time only.

Upvotes: 2

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