Hi,
Be aware of this little trap :
When using a decode for instance to eliminate default values,
make sure the format is oke:

SELECT decode( t.input_date
, to_date('19000101','yyyymmdd')
, to_date(Null)
, t.input_date)
FROM MyTable t;

When not using a to_date(Null), it may be converted to char
(when it is the first record) and thereby truncate the real dates. When standard representation = mm/dd/yy
a date like 02/15/99 may become 02/15/2099 after this selection.