The default password for user ID DBA for all databases is sql. You should change this password to prevent unauthorized access to your database.
To change the DBA password, you must have DBA or PERMS ADMIN authority.
If you are using dbisql, it is a good idea to put your permission grants into a command file for reference and so that it can be modified and run again if it is necessary to recreate the permissions.
ALTER USER DBA IDENTIFIED BY new_password