Continnum 1.2.2 doesn't work with Oracle

[Lustig, Marc (Allianz Deutschland, externer Mitarbeiter)]

2008-11-14 09:34:13,476 [main] ERROR JPOX.RDBMS  - Error thrown executing 
CREATE TABLE CHANGESET
(
    CHANGESET_ID NUMBER NOT NULL,
    AUTHOR VARCHAR2(255) NULL,
    CHANGECOMMENT VARCHAR2(8192) NULL,
    CHANGEDATE NUMBER NOT NULL,
    ID VARCHAR2(255) NULL,
    MODEL_ENCODING VARCHAR2(255) NULL,
    CHANGES_SCMRESULT_ID_OID NUMBER NULL,
    CHANGES_INTEGER_IDX NUMBER(10) NULL
) : ORA-00910: specified length too long for its datatype
 
java.sql.SQLSyntaxErrorException: ORA-00910: specified length too long for its 
datatype
 

--> for Oracle, VARCHAR2 max size is 4000

I was unable to find the JDO entity-definition in the continuum webapp.

Please give a hint for the quick-fix.