text: -- create class with numberic using every length and 
  create class c_n (
  
      c1 NUMERIC PRIMARY KEY,
      c2 NUMERIC(5) DEFAULT 0 NOT NULL,
      c3 NUMERIC(9,4) UNIQUE NOT NULL,
      c4 NUMERIC(4,4) SHARED 0.1 NOT NULL
      );
  drop c_n;
  