oracle数据库，表被锁，如何解锁？

4.批量解锁
declare cursor mycur is
select b.sid,b.serial# from v$locked_object a,v$session b
where a.session_id = b.sid group by b.sid,b.serial#;

begin
for cur in mycur
loop
execute immediate ( 'alter system kill session '''||cur.sid || ','|| cur.SERIAL# ||''' ');
end loop;
end;