As HANA administrator,
we need to work on HANA database users. In case we need set user password
validity to unlimited. Its simple we can do same by just executing 2 queries. 
1: We need to
create user with password.
                             create user HANA_USER password
"Welcome123";
2: Once user
is created then set validity by running below query
                              alter user HANA_USER DISABLE PASSWORD LIFETIME;
Note: 
We need to
run these queries on respective TENANT or SYSTEM DB. 
To running queries we have sufficient privilege  
