Referencing Oracle user defined types over DBLINK?

Question

I\'m working in two different Oracle schemas on two different instances of Oracle. I\'ve defined several types and type collections to transfer data between these schemas.

Answer 1

I have read the Oracle Documentation and it is not very difficult.

You need to add an OID to your type definitions in both databases.

You can use a GUID as OID.

SELECT SYS_OP_GUID() FROM DUAL; 

SYS_OP_GUID()
--------------------------------
AE34B912631948F0B274D778A29F6C8C

Now create your UDT in both databases with the SAME OID.

create type testlinktype oid 'AE34B912631948F0B274D778A29F6C8C' as object
( v1 varchar2(10) , v2 varchar2(20) );
/

Now create a table:

create table testlink 
( name testlinktype);

insert into testlink values (testlinktype ('RC','AB'));

commit;

Now you can select from the table via the dblink in the other database:

select * from testlink@to_ora10;

NAME(V1, V2)
--------------------------
TESTLINKTYPE('RC', 'AB')

If you get error ORA-21700 when you try to select via the dblink the first time, just reconnect.

Answer 2

I think the underlying issue is that Oracle doesn't know how to automatically serialize/deserialize your custom type over the wire, so to speak.

Your best bet is probably to pass an XML (or other) representation over the link.