firebase recycler视图加载速度非常慢

Question

我的Firebase RecyclerView花费了太多时间来加载数据。我在许多片段中使用RecyclerView，但它们不会出现任何问题。但我不知道这里有什么问题。它会在5分钟或更长时间后加载数据。有人知道这个问题吗？

我的主要片段类：

public class UserPrescriptionView extends Fragment {
    private DatabaseReference dataRef;
    private String uid;
    private FirebaseAuth mAuth;
    private Query mQuery;
    private RecyclerView recycle;
    private TextView noCnslt,dctName,cnsltDate;
    private ProgressBar progress;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup 
    container, @Nullable Bundle savedInstanceState) {
        if (container!=null){
            container.removeAllViews();
        }
        View v=inflater.inflate(R.layout.activity_user_prescription_view,container,false);
        mAuth=FirebaseAuth.getInstance();
        dataRef= FirebaseDatabase.getInstance().getReference();
        uid=mAuth.getCurrentUser().getUid();
        recycle= (RecyclerView) v.findViewById(R.id.user_prscptn_view_recycle);
        noCnslt= (TextView) v.findViewById(R.id.activity_user_prescription_noCnslt);
        recycle.setHasFixedSize(true);
        LinearLayoutManager llm = new LinearLayoutManager(getActivity());
        progress= (ProgressBar) v.findViewById(R.id.user_prscptn_progress);
        noCnslt.setVisibility(View.GONE);
        llm.setOrientation(LinearLayoutManager.VERTICAL);
        recycle.setLayoutManager(llm);
        recycle.addItemDecoration(new SimpleDividerItemDecoration(getActivity()));
        dctName= (TextView) v.findViewById(R.id.user_prscptn_dctName);
        cnsltDate= (TextView) v.findViewById(R.id.user_prscptn_cnsltOn);
        dctName.setVisibility(View.GONE);
        cnsltDate.setVisibility(View.GONE);
        return v;
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        mQuery=dataRef.child("Medical Record").orderByChild("uid").equalTo(uid);
         FirebaseRecyclerAdapter<DocPrcptn,DocPrcptnViewHolder> adapter=new FirebaseRecyclerAdapter<DocPrcptn, DocPrcptnViewHolder>(
                DocPrcptn.class,
                R.layout.user_prscrptn_view,
                DocPrcptnViewHolder.class,
                mQuery
                ) {
             @Override
            protected void populateViewHolder(DocPrcptnViewHolder viewHolder, final DocPrcptn model, final int position) {
                    progress.setVisibility(View.GONE);
                    dctName.setVisibility(View.VISIBLE);
                    cnsltDate.setVisibility(View.VISIBLE);
                    viewHolder.setDate(model.getDate().substring(0,11));
                    viewHolder.setDoctor("Dr "+model.getDoctor());

                final String key=getRef(position).getKey();
                viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        FragmentTransaction ft=getFragmentManager().beginTransaction();
                        Prescription pc=new Prescription();
                        Bundle b=new Bundle();
                        b.putString("key",key);
                        pc.setArguments(b);
                        ft.replace(R.id.activity_user_prescription_recycle,pc);
                        ft.addToBackStack(null);
                        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
                        ft.commit();
                    }
                });

            }

            @Override
            public void onDataChanged() {
                if (getItemCount()==0){
                    progress.setVisibility(View.GONE);
                    noCnslt.setVisibility(View.VISIBLE);

                }
                super.onDataChanged();
            }
        };

        recycle.setAdapter(adapter);
    }
    public static class DocPrcptnViewHolder extends RecyclerView.ViewHolder{
        private TextView docName,docDate;
        public DocPrcptnViewHolder(View itemView) {
            super(itemView);
            docName= (TextView) itemView.findViewById(R.id.user_prscptn_view_name);
            docDate= (TextView) itemView.findViewById(R.id.user_prscptn_view_date);

        }
        public void setDoctor(String name){
             docName.setText(name);
        }
        public void setDate(String date){
            docDate.setText(date);
        }
    }
}

我的模特课：

public class DocPrcptn {
    public DocPrcptn() {
    }
    public String doctor,date;

    public DocPrcptn(String doctor, String date) {
        this.doctor = doctor;
        this.date = date;
    }

    public String getDoctor() {
        return doctor;
    }

    public void setDoctor(String doctor) {
        this.doctor = doctor;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }
}

任何线索？感谢。