Oracle Database Discussions

hi,

i am facing a problem with flashback querry.

scenario :
i deleted data from emp table .
after that i altered table by modifying one column from NUMBER(2) to VARCHAR2(2).
after altering the table when i try to see the data by using flashback query it is throwing error.

select * from room_master as of timestamp(sysdate-2);

select * from room_master as of scn 681559032;

select * from flashback_transaction_query
where table_name = 'EMP'

Error message : ORA-01466 : Unable to read data -table definitions has changed

please advice me to sort out the issue.

Thanks in advance