select x,x,x,
to_char(decode(trans_ukey1, 'HOME', rate1, trans_ukey1))
department
from x
as per my knowledge the rate1 column or trans_ukey1 conlumn
must have a value of lengrh 40, thats why the col is created with 40.
Try inserting a value of 233 length in rate1 column or trans_ukey1 column...