SQL> alter session set nls_date_format='yyyy-mm-dd hh24:mi:ss'; 
Session altered. 

SQL> select username,lock_date from dba_users where username='TEST'; 
USERNAME LOCK_DATE 
TEST 2009-03-10 08:51:03 

SQL> alter user test account unlock; 
User altered. 

10-MAR-2009 08:51:03 * (CONNECT_DATA=(SID=lhoms)(SERVER=DEDICATED)(CID=(PROGRAM=Oracle)(HOST=omstestdb)(USER=oraoms))) * (ADDRESS=(PROTOCOL=tcp)(HOST=10.69.1.11)(PORT=49434)) * establish * lhoms * 0
10-MAR-2009 08:51:03 * (CONNECT_DATA=(SID=lhoms)(SERVER=DEDICATED)(CID=(PROGRAM=oracle)(HOST=omstestdb)(USER=oraoms))) * (ADDRESS=(PROTOCOL=tcp)(HOST=10.69.1.11)(PORT=49435)) * establish * lhoms * 0

select * from dba_profiles 

alter profile default limit FAILED_LOGIN_ATTEMPTS 30; 

alter profile default limit FAILED_LOGIN_ATTEMPTS unlimited;