Get an error when creating MV

Question

/*==============================================================*/
/* View: VW_DOC_GEN_PKG */
/*==============================================================*/
create materialized view log on DOC_GEN_DOC TABLESPACE DATADYNM;
create materialized view log on DOC_GEN_REQ TABLESPACE DATADYNM;
create materialized view log on PKG_DOC TABLESPACE DATADYNM;
create materialized view log on PKG_REQ TABLESPACE DATADYNM;
CREATE MATERIALIZED VIEW VW_DOC_GEN_PKG
TABLESPACE DATADYNM storage ( initial 128K )
BUILD IMMEDIATE
REFRESH FAST ON COMMIT
ENABLE QUERY REWRITE
AS
SELECT DOC_GEN_DOC.DOC_GEN_REQ_ID,
DOC_GEN_DOC.UIL,
DOC_GEN_DOC.DOC_GEN_DOC_ID,
DOC_GEN_DOC.DOC_GEN_DOC_DTTM,
DOC_GEN_DOC.DOC_GEN_DOC_SEQ,
DOC_GEN_DOC.FRM_VER_TXT,
DOC_GEN_DOC.FRM_NUM,
DOC_GEN_DOC.FRM_NM,
DOC_GEN_REQ.PKG_NM,
DOC_GEN_REQ.DOC_GEN_DTTM,
DOC.BATCH_NM
FROM DOC_GEN_REQ
INNER JOIN DOC_GEN_DOC
ON (DOC_GEN_DOC.DOC_GEN_REQ_ID = DOC_GEN_REQ.DOC_GEN_REQ_ID)
INNER JOIN DOC
ON (DOC_GEN_DOC.UIL = DOC.UIL)
WHERE (DOC.DLTD_IND = 'N')
UNION ALL
SELECT PKG_DOC.PKG_REQ_ID DOC_GEN_REQ_ID,
PKG_DOC.UIL,
PKG_DOC.PKG_DOC_ID DOC_GEN_DOC_ID,
PKG_DOC.PKG_DOC_DTTM DOC_GEN_DOC_DTTM,
PKG_DOC.PKG_DOC_SEQ_NUM DOC_GEN_DOC_SEQ,
'' FRM_VER_TXT,
NULL FRM_NUM,
'' FRM_NM,
PKG_REQ.PKG_NM,
PKG_REQ.PKG_REQ_DTTM DOC_GEN_DTTM,
DOC.BATCH_NM
FROM PKG_REQ
INNER JOIN PKG_DOC
ON (PKG_DOC.PKG_REQ_ID = PKG_REQ.PKG_REQ_ID)
INNER JOIN DOC
ON (PKG_DOC.UIL = DOC.UIL)
WHERE (DOC.DLTD_IND = 'N');
ORA-12054: cannot set the ON COMMIT refresh attribute for the materialized view
what is wrong?
thank you

Answer 1

I checkec docs, didn't find anything yet...I'm not convinced you ever tried to do so.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_6002.htm#SQLRF01302
ON COMMIT Clause
Specify ON COMMIT to indicate that a fast refresh is to occur whenever the database commits a transaction that operates on a master table of the materialized view. This clause may increase the time taken to complete the commit, because the database performs the refresh operation as part of the commit process.
Restrictions on Refreshing ON COMMIT
    *      This clause is not supported for materialized views containing object types.