All sap hana users are created by default with a password expiration date. It is set at 182 days from the time the user has been created or from the time the password has been modified.
To ensure the stability and performance of the overall system or for security reasons, you can prevent certain system properties from being changed by tenant database administrators, for example, properties related to resource management. A configuration change blacklist is available for this purpose. You configure the blacklist in the SAP HANA cockpit.
You want to manage and control the memory usage of your multiple-container system by configuring global allocation limit for individual tenant databases.
A sap hana user is created with a life span of 182 days by default. The message "The password for database user < user name > will expire on 2018-07-17 at 15:17:35" .If the password expires, the user will be locked.] will be triggered every day in hana studio during the 14 days before the dead line.
Resetting the SYSTEM User's Password in the admin guide for SP7 discusses how to do this: http://help.sap.com/hhxe/SAP_HHXE_Administration_Guide_en.pdf