Activating OLD used password for FND User oracle apps

Oracle Applications by default restrict you to reset the old earlier used password. The reason being all OLD passwords are stored in FND_USER_PREFERENCES table. We can use the following queries to see all the entries (though all passwords will be in encrypted format)

select *
from applsys.fnd_user_preferences
where user_name = 'SYSADMIN'
and module_name = 'PWDVALREUSE'

In order to reset/reuse the earlier USED password, one can delete all the entries from above mentioned table

DELETE
from applsys.fnd_user_preferences
where user_name = 'SYSADMIN'
and module_name = 'PWDVALREUSE';

COMMIT;

Oracle Apps: How to change Oracle application user password from plsql

Generally Oracle applications user password is reset/changed through the System administrator> Define user form.
But sometimes developers/testers need to do a quick test using some user's credentials in dev/test instance and in these situations, you lose time if you follow the above procedure just for resetting the user password.

To address this pain, developers can use fnd_user_pkg.changepassword API to change the password of an Oracle application user.

This returns boolean value and has two input parameters,

1. User name
2. Password

Following PL/SQL block can be used to reset password to welcome@123,

begin
if fnd_user_pkg.changepassword('USER_NAME','welcome@123') then
null;

end if;
end;