Insert some values for which the combination of dim_1 and dim_2 is unique:
insert into tq84_tab values (1, 'aaa', 17, 9);
insert into tq84_tab values (1, 'bbb', 12, 7);
insert into tq84_tab values (1, 'ccc', 4, 12);
insert into tq84_tab values (2, 'aaa', 2, 6);
Inserting this record will cause ORA-32638: Non unique addressing in MODEL dimensions error with following select statement because values of specified dimensions are not unique:
insert into tq84_tab values (1, 'bbb', 12, 7);
Select statement to try model clause
select * from tq84_tab
model
dimension by (dim_1, dim_2)
measures (val_1, val_2)
rules ( )
;