Single permission with a dependent table

Example 3: Using a single permission with the users defined in a dependent table.

     CREATE SCHEMA MY_LIB	
     CREATE SCHEMA RCAC_DEPENDENT  
     CREATE TABLE MY_LIB.PERMISSION_TABLE (COLUMN1 INT)
     CREATE TABLE RCAC_DEPENDENT.USERS (USERNAME CHAR (10))
     INSERT INTO RCAC_DEPENDENT.USERS
            VALUES('USER1     '),('USER2     '),('USER3     ')
     CREATE TABLE MY_LIB.PERMISSION_TABLE (FIELD1 INT)
     CREATE PERMISSION MY_LIB.PERM1 ON MY_LIB.PERMISSION_TABLE
            FOR ROWS WHERE
            CURRENT_USER IN (SELECT USERNAME FROM RCAC_DEPENDENT.USERS)
            ENFORCED FOR ALL ACCESS ENABLE
     ALTER TABLE MY_LIB.PERMISSION_TABLE ACTIVATE ROW ACCESS CONTROL
     /***********************************************************************/
     /* Sign on as USER1                                                    */
     /***********************************************************************/
     INSERT INTO MY_LIB.PERMISSION_TABLE  VALUES(1)    /* Allowed.          */

The advantage of a single permission checking a dependent table is that when adding another user, the permission does not have to change. The disadvantage is the performance consideration of querying the dependent table.