Refer the section Database Prerequisites
Basically, you need to run these two scripts present under the
<installsource>:\Single Sign On\DBScripts\SSOServer\schema\mssql\rsaIMSLiteMSSQLSetupTablespaces.sql and rsaIMSLiteMSSQLSetupUsers.sql
In these two files replace the text "change me" with values appropriate for your env.
Regards
Girish