Migrating V9 to V10: Update XML Fragment CLOB does not work anymore

Question

I have an XML Schema that contains an element, named Operazione, mapped to a CLOB.
I just migrate to Oracle 10.1.0.2.0 from version 9.2.0.2.0 and the code I developed does not work anymore.
To get a CLOB on v 9.2.0.2.0 I issued the following statement:
select extractValue(value(p),'/operazione.log/Operazione') from XMT_OPERAZIONE_LOG p
where existsNode(value(p),'/operazione.log/Journal[NumeroElettronico=1234567890]') = 1
To make it working on V10 I have to change it as follow:
select extract(value(p),'/operazione.log/Operazione').getClobVal() from XMT_OPERAZIONE_LOG p
where existsNode(value(p),'/operazione.log/Journal[NumeroElettronico=1234567890]') = 1
So using extract intead of extractValue and adding getClobVal() I was able to read the CLOB.
The problem that I was not able to solve is related to CLOB update. In V9 just adding the “for update” clause I was able to change the CLOB value on DB.
In V10 if I run the V9 statement I get the error:
ORA-03113: end-of-file on communication channel
If I use the statement modified for V10, adding the “for update” clause, I get the CLOB and I can change the CLOB value but nothing goes on the DB. Probably I am working on a copy of the DB CLOB.
If I remove the getClobVal() I get an OPAQUE type that I can use on a XMLType but, still, nothing is stored on DB.
Any suggestion ?
I tried with both OCI and Thin Client

Answer 1

Can anybody help me ?
Is it better to use different strategies ( eg. Stored Procedure, DBMS_XMLSTORE etc, etc. ) ?
Any experience updatating XML Fragment CLOB on Oracle V10 ?