Locking User Accounts

SQL>alter user venu1 account lock;

SQL>conn venu1/venu1

                ORA-28000 : the account is locked

SQL>conn / as sysdba

SQL>alter user venu1 account unlock;

SQL>conn venu1/venu1

SQL>alter user venu1 identified by madhu;

                To change the password of the user.

SQL>select * from all_users;