text: --+ holdcas on;
  --  after creating PK-FK, chage the authorization of PK class
  
  call login('dba','') on class db_user;
  create user user1;
  create user user2;
  
  call login('user1', '') on class db_user ;
  
  create table xoo ( id int PRIMARY KEY); 
  insert into xoo values(10000); 
  grant all on xoo to user2; 
  
  call login('user2', '') on class db_user ;
  
  
  create table yoo ( a int ,b VARCHAR(10),c INT,FOREIGN KEY (c) REFERENCES xoo(id)); 
  insert into yoo values(1,'ssss',10000); 
  
  call login('user1', '') on class db_user ;
  
  REVOKE all on xoo from user2;
  
  call login('dba','') on class db_user;
  
  
  drop TABLE yoo;
  drop TABLE xoo;
  
  drop user user1;
  drop user user2;
  
  
  --+ holdcas off;
  