Oracle ADT columns

Hi,
has anybody worked with oracle adt columns in the Rails ?
I have a table with a column what has DER data type, described below:
create or replace TYPE “DER” AS OBJECT
(READABLE VARCHAR2(4000)
,DER BLOB
)
obviously as a result I always have ‘unsupported datatype’ error
message.
I’ve tried to add to oracle adapter and then to oci8 processing of
this data type but … in vain.

Please, could you help me and explain how to add oracle user data type
handling?

Thanks.