ORA-28000: the account is locked error getting frequently

I am getting the error :

 ORA-28000: the account is locked 

Is this a DB Issue? When I unlock user account using the command ALTER USER username ACCOUNT UNLOCK temporarily it will be OK. Then after some time the same account lock happens again.

The database using is oracle XE

Does anybody else have the same issue?

One of the reasons of your problem could be the password policy you are using.

And if there is no such policy of yours then check your settings for the password properties in the DEFAULT profile with the following query:

SELECT resource_name, limit
FROM dba_profiles 
WHERE profile = 'DEFAULT'
AND resource_type = 'PASSWORD';

And If required, you just need to change the PASSWORD_LIFE_TIME to unlimited with the following query:

ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED;

And this Link might be helpful for your problem.

Way to unlock the user :

$ sqlplus  /nolog
SQL > conn sys as sysdba
SQL > ALTER USER USER_NAME ACCOUNT UNLOCK;

and open new terminal

SQL > sqlplus / as sysdba
connected
SQL > conn username/password  //which username u gave before unlock

• it will ask new password:password
• it will ask re-type password:password
• press enter u will get loggedin

Here other solution to only unlock the blocked user. From your command prompt log as SYSDBA:

sqlplus "/ as sysdba"

Then type the following command:

alter user <your_username> account unlock;