Is Realm's .where faster than filtering a list manually? - filtering

Question

I am creating a project using a realm database.
I also have a lot of lists which I wish to filter while the user types.
The biggest one of them will probably be the list of customers
Currently I am using realm by using a wrapper class for each object (if anyone has a better suggestion I'm definitely open to it)
The objects I am using are like this:
public class Customer_Realm extends RealmObject{
private int _id;
private String _name; //...etc
public int get_id(){ return _id; }
public void set_id(int id) { _id = id;}
//etc
}
Public class Customer() {
Customer_Realm _base;
public Customer(Customer_Realm base) { _base = base;}
public int get_id(){ return _base.get_id(); }
public void set_id(int id) { _base.set_id(id);}
//...etc
}
Along with this I have an ArrayListAdapter for customer objects. My question is, would this:
public class CustomerAdapter extends ArrayListAdapter<Customer> {
List<Customer> _customers;
String _filter = null;
public void set_filter(string name) {
_filter = name;
notifyDataSetChanged();
}
#override
public int getCount(){
return get_visible().count();
}
public Customer getItem(int position){
return get_visible().get(position);
}
public List<Customer> get_visible() {
if (_filter == null)
return _customers;
List<Customer> visible = new ArrayList<Customer> ();
foreach (Customer c : _customers){
if (c.get_name().contains(_filter)
visible.add(c);
}
return visible;
}
}
Or would this be better?
public class CustomerAdapter extends ArrayListAdapter<Customer> {
Realm _database;
String _filter = null;
public void set_filter(string name) {
_filter = name;
notifyDataSetChanged();
}
#override
public int getCount(){
return get_visible().count();
}
public Customer getItem(int position){
return get_visible().get(position);
}
public List<Customer> get_visible() {
RealmResults<Customer_Realm> result = null;
if (_filter == null)
result = _database.allObjects(Customer_Realm.class);
else
result = _database.where(Customer_realm.class).contains("_name",_filter);
List<Customer> visible = new ArrayList<Customer> ();
foreach (Customer_Realm c : result){
visible.add(new Customer(c));
}
return visible;
}
}
Unfortunately my database contains only a small sample of data(and realm for windows does not have an editor so I can enter data manually) so when I try either implementation I do not see any difference, I was wondering if anyone has any experience with what happens when you use such an implementation with a large number of data
Thanks in advance for any help you can provide