WITH MyCommonTableExpression
AS
  (
  SELECT 
    a.table_name as child_table, 
    b.table_name parent_table,
    colb.column_name as child_column

  from user_constraints a
    INNER JOIN user_constraints  b     ON  a.r_constraint_name  = b.constraint_name
    INNER JOIN user_cons_columns conb  ON  conb.constraint_name = b.constraint_name
    INNER JOIN user_tab_columns  colb  ON  colb.table_name      = conb.table_name 
                                       AND colb.column_name     = conb.column_name
  WHERE a.constraint_type = 'R'
    
   )
   SELECT 
     parent_table, 
     child_table, 
     child_column,
     1 as lvl
   FROM MyCommonTableExpression
   WHERE parent_table='GMACT'
     START WITH parent_table = 'GMACT'
   CONNECT BY PRIOR child_table = parent_table

select * from all_views where LEFT(view_name,5) = 'USER_'