SPIsuper is a database user created only in SQL Server during the database setup. This schema is used when you initialize and define a domain, and also when you back up, upgrade, or delete a domain. Furthermore, this schema is used when you run any DBA menu option in the System Administration window.
The schema login is shared for all databases you create in a particular SQL Server instance. For example, if you create SPI1 and SPI2 databases in the same instance, each database contains the SPIsuper schema but, at the instance level, both schemas share the same login. The login name is SPIsuper and the password is spisuper_pwd (lower case). Both the login name and password are set permanently in the software.