Oracle - Temporarily Changing a User's Password

Another interesting, undocumented command syntax is the "alter user ... using values ..."

To temporarily change a user's password then set it back, take a note of the PASSWORD field in DBA_USERS. Change the password and then set it back to what it was:

SQL> select username, password from dba_users where username='BUBBA';

USERNAME PASSWORD
------------------------------ ------------------------------
BUBBA 3104BC5BB78B55BE

SQL> alter user bubba identified by bubba;
User altered.

SQL> conn bubba/bubba
Connected.

SQL> conn / as sysdba
Connected.

SQL> select username, password from dba_users where username='BUBBA';

USERNAME PASSWORD
------------------------------ ------------------------------
BUBBA 7D2D7383FC9288B7

SQL> alter user bubba identified by values '3104BC5BB78B55BE';
User altered.

SQL> select username, password from dba_users where username='BUBBA';

USERNAME PASSWORD
------------------------------ ------------------------------
BUBBA 3104BC5BB78B55BE