CREATE TABLE horizontal
( key_column NUMBER
, val_1      NUMBER
, val_2      NUMBER
, ...
, val_n      NUMBER
);

ALTER TABLE horizontal ADD PRIMARY KEY (key_column);


CREATE TYPE my_parent_type AS OBJECT
( dummy CHAR(1) ) NOT FINAL;

CREATE TYPE my_type UNDER my_parent_type
( val_1      NUMBER
, val_20     NUMBER
, val_500    NUMBER
);

CREATE TABLE ora_objects
( key_column NUMBER
, vals       my_parent_type
);

ALTER TABLE ora_objects ADD PRIMARY KEY (key_column);


CREATE TABLE vertical
( key_column  NUMBER
, value_type  NUMBER
, val         NUMBER
);

ALTER TABLE vertical ADD PRIMARY KEY (key_column, value_type);

SELECT
   val_1
 + val_30
FROM horizontal
WHERE key_column IN (:1);

SELECT
   TREAT(val AS my_type).val_1
 + TREAT(val AS my_type).val_30
FROM ora_objects
WHERE key_column IN (:1);

SELECT
   MAX(DECODE(value_type,:1,val,NULL))
 + MAX(DECODE(value_type,:2,val,NULL))
FROM vertical
WHERE key_column IN (:3);