SQL> conn scott / as sysdba
Enter password:
Connected.
SQL> select * from sys.user_history$;

no rows selected

SQL> select * from user_history$;

no rows selected

SQL> alter user scott identified by tejajun20;

User altered.

SQL> select * from user_history$;

no rows selected

SQL> CREATE PROFILE my_profile LIMIT
  2    FAILED_LOGIN_ATTEMPTS 3  -- Account locked after 3 failed logins.
  3    PASSWORD_LOCK_TIME 5     -- Number of days account is locked for. UNLIMITED required explicit unlock by DBA.
  4    PASSWORD_LIFE_TIME 30    -- Password expires after 90 days.
  5    PASSWORD_GRACE_TIME 3    -- Grace period for password expiration.
  6    PASSWORD_REUSE_TIME 120  -- Number of days until a specific password can be reused. UNLIMITED means never.
  7    PASSWORD_REUSE_MAX 10    -- The number of changes required before a password can be reused. UNLIMITED means never.
  8  /

Profile created.

SQL> ALTER USER scott PROFILE my_profile;

User altered.

SQL> select * from sys.user_history$;

no rows selected

SQL> alter user scott identified by tejajun20;

User altered.

SQL> select * from user_history$;

     USER# PASSWORD                       PASSWORD_
---------- ------------------------------ ---------
        54 624AA21960E83872               05-JAN-10

SQL> alter user scott identified by TEJAJUN20;
alter user scott identified by TEJAJUN20
*
ERROR at line 1:
ORA-28007: the password cannot be reused


SQL> alter user scott identified by tiger;

User altered.

SQL> select * from user_history$;

     USER# PASSWORD                       PASSWORD_
---------- ------------------------------ ---------
        54 624AA21960E83872               05-JAN-10
        54 F894844C34402B67               05-JAN-10

SQL>

SQL> desc dba_users
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 USERNAME                                  NOT NULL VARCHAR2(30)
 USER_ID                                   NOT NULL NUMBER
 PASSWORD                                           VARCHAR2(30)
 ACCOUNT_STATUS                            NOT NULL VARCHAR2(32)
 LOCK_DATE                                          DATE
 EXPIRY_DATE                                        DATE
 DEFAULT_TABLESPACE                        NOT NULL VARCHAR2(30)
 TEMPORARY_TABLESPACE                      NOT NULL VARCHAR2(30)
 CREATED                                   NOT NULL DATE
 PROFILE                                   NOT NULL VARCHAR2(30)
 INITIAL_RSRC_CONSUMER_GROUP                        VARCHAR2(30)
 EXTERNAL_NAME                                      VARCHAR2(4000)

SQL> desc dba_profiles
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 PROFILE                                   NOT NULL VARCHAR2(30)
 RESOURCE_NAME                             NOT NULL VARCHAR2(32)
 RESOURCE_TYPE                                      VARCHAR2(8)
 LIMIT                                              VARCHAR2(40)

SQL>