create undo tablespace UNDOTBS2 datafile 'D:oracleproduct10.2.0oradata tonlineUNDOTBS02.DBF' size 500m reuse autoextend on next 100m;
alter system set undo_tablespace=UNDOTBS2 scope=both;
drop tablespace UNDOTBS1 INCLUDING CONTENTS AND DATAFILES CASCADE CONSTRAINTS;
shutdown immediate;
startup mount;
alter database open;