Creating an index for a variable size opaque type

I have an opaque type like this: create opaque type AsnOctetString( internallength = variable, maxlen = 4096, alignment = 4 ); I may NOT be ABLE to CHANGE this type and its assosiated functions (compare etc), which will be registered with the server, since they are used by other systems. I an creating a table like this: CREATE TABLE testTable( oid AsnOctetString, reader VARCHAR(10), fileName VARCHAR(10), readStatus integer) LOCK MODE ROW I want to create an index for oid, BUT the type is too big for me to do this. Since the type's size is variable, I thought I should be able to declare the field of the same type only smaller so that I can create an index for it. I tried this: CREATE TABLE testTable( oid AsnOctetString(20), reader VARCHAR(10), fileName VARCHAR(10), readStatus integer) LOCK MODE ROW BUT the syntax appears to be wrong. I have created an index for an opaque type before, but that type was small enouugh in size. How do I say this one wonte hold anything too big and manage to create an index for it ? Hope some-one can help. Andrew H. sending to informix-list