0015731: The locator selector takes long to return the data when there are a lot of locators on the table

CREATE OR REPLACE FUNCTION ego_create_locator()
  RETURNS void AS
$BODY$ DECLARE 
   v_x NUMERIC:=4;
   v_y NUMERIC:=1;
   v_z NUMERIC:=1;
   v_name character varying (32);
BEGIN
  WHILE (v_z<9000) LOOP
  v_name:=TO_CHAR(v_x) || '-' || TO_CHAR(v_y) || '-' || TO_CHAR(v_z);
  insert into m_locator values(get_uuid(),'1000000','0','Y',now(),'0',now(),'0',v_name,'1000000','50','N',TO_CHAR(v_x),TO_CHAR(v_y),TO_CHAR(v_z));
  v_z:=v_z+1;
  END LOOP;
  
END ; $BODY$
  LANGUAGE 'plpgsql' VOLATILE
  COST 100;