I have 1000 documents in a single collection in Cloud Firestore, is it possible to fetch random documents?
Say for example: Students is a collection in          
        
Based on @ajzbc answer I wrote this for Unity3D and its working for me.
FirebaseFirestore db;
    void Start()
    {
        db = FirebaseFirestore.DefaultInstance;
    }
    public void GetRandomDocument()
    {
       Query query1 = db.Collection("Sports").WhereGreaterThanOrEqualTo(FieldPath.DocumentId, db.Collection("Sports").Document().Id).Limit(1);
       Query query2 = db.Collection("Sports").WhereLessThan(FieldPath.DocumentId, db.Collection("Sports").Document().Id).Limit(1);
        query1.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask1) =>
        {
             if(querySnapshotTask1.Result.Count > 0)
             {
                 foreach (DocumentSnapshot documentSnapshot in querySnapshotTask1.Result.Documents)
                 {
                     Debug.Log("Random ID: "+documentSnapshot.Id);
                 }
             } else
             {
                query2.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask2) =>
                {
                    foreach (DocumentSnapshot documentSnapshot in querySnapshotTask2.Result.Documents)
                    {
                        Debug.Log("Random ID: " + documentSnapshot.Id);
                    }
                });
             }
        });
    }