ISSUE CLARIFICATION
====================
After dropping the materialized view,while trying to drop the underlying table,
it failed with below error

When I try to drop the table it gives "ORA-12083: must use DROP MATERIALIZED
VIEW ..." .

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ISSUE VERIFICATION
===================
Verified with error description above.

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CAUSE DETERMINATION
====================
This is because of the Bug 4287115.
This is a known issue in 9i , which is fixed in 10g.

CAUSE JUSTIFICATION
====================
the bug description clearly matches the issue here.

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POTENTIAL SOLUTION(S)
======================
To workaround the problem , connected as sys run the following update statement.
The following update should update only one row. In case if it updates more
than one row, then rollback the transaction, which means that this workaround
does not apply to your case.

connect sys/ as sysdba
update tab$ set property = property - 100663296 where
obj# in (select obj# from obj$ where name='OT_CR_ITEM_X' and
owner# in (select USER_ID from all_users where USERNAME=''));
commit;

alter system flush shared_pool;
alter system flush shared_pool;
alter system flush shared_pool;

connect /
Now try dropping the table & it should go through fine.

POTENTIAL SOLUTION JUSTIFICATION(S)
====================================
This is the recommended solution.

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SOLUTION / ACTION PLAN
=======================
Hi Chunpeng,

This problem is not fixed in 9i,but you can try the workaround given above.
this is fixed in 10g.