text: -- create vclass attribute using shared constraints
  set system parameters 'create_table_reuseoid=no';
  
  create class picture
  (caption set string,
   image string);
   
   insert INTO picture VALUES ({'s'},'s');
   
   create vclass meal
  class attribute (meal_type string shared 'as')
  (menu picture);
   
   select * FROM db_attribute WHere class_name='meal'  order by 1;
   
   
   SELECT * FROM meal;
   
   
   DROP picture;
   
   DROP meal;
  
  set system parameters 'create_table_reuseoid=yes';
  