Database Software

I created a MV base on some tables in order to improve the querey speed.
but the mv I have created falied to refresh fast.
because there are two same table in the from clause:
jcdm jc1,jcdm jc2

create materialized view temp_mv
nologging
pctfree 0
storage (initial 2048k next 2048k pctincrease 0)
parallel
build immediate
refresh force
on demand
as
select
TAB_GSHX.rowid hx_rid,
TAB_GSHD.rowid hd_rid ,
JC1.rowid jc1_rid ,
JC2.rowid jc2_rid ,
YSHD_ID HXID,
JC1.JCDM QFD,
JC2.JCDM JLD
FROM
TAB_GSHX,
TAB_GSHD,
jCDM JC1,
JCDM JC2
WHERE
YSHD_ID=YSHX_ID
AND YSHD_QFD=JC1.JBJC_ID
AND YSHD_JLD=JC2.JBJC_ID
AND TO_CHAR(YSHX_time,'YYYYMMDD')='20030101'


the column msgtxt of the table MV_CAPABILITIES_TABLE is :
"the multiple instances of the same table or view" and " one or more joins present in mv".

How can I succeed in fast refresh the above temp_mv!!!

thanks.