Based on what I've read thus far Albert is that the installation DVD has scripts for the different databases that you run prior to the installation to prepare for SSO.
VMware vSphere 5.1 Documentation Center
Database Prerequisites
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Verify that your vCenter Server database meets the database requirements. See vCenter Server Database Configuration Notes and Preparing vCenter Server Databases.
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Create a vCenter Server database, unless you plan to install the bundled database.
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Create a vCenter Single Sign-On database, unless you plan to install the bundled database.
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If you are using an existing database for Single Sign-On, you must create a database user (RSA_USER) and database administrator (RSA_DBA) to use for the Single Sign-On database installation and setup. To create these users, run the script rsaIMSLiteDBNameSetupUsers.sql. The script is included in the vCenter Server installer download package, at vCenter Server Installation directory\Single Sign On\DBScripts\SSOServer\Schema\your_existing_database..
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If you are using an existing database with your vCenter Single Sign-On installation or upgrade, make sure that the table spaces are named RSA_DATA and RSA_INDEX. Any other table space names will cause the vCenter Single Sign-On Installation to fail.
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If you are using an existing database for Single Sign-On, to ensure that table space is created for the database, run the script rsaIMSLite<DBName>SetupTablespaces.sql. The script is included in the vCenter Server installer download package, at vCenter Server Installation directory\Single Sign On\DBScripts\SSOServer\Schema\your_existing_database. You can run this script prior to the installation, or during the installation, when you are prompted by the installer. You can leave the installer to run the script, and resume the installer after you run the script.
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If you are using an existing Microsoft SQL Server database for Single Sign-On, and you want to use a dynamic port, you must provide a named instance for the SQL database during the Single Sign-On installation. The instance name created during Microsoft SQL Server installation usually defaults to MSSQLSERVER. For non-default instance names, you can determine the instance name after Microsoft SQL Server is installed by using the SQL Configuration Manager. Under SQL Server Network Configuration, the SQL Configuration Manager lists all available instances of the SQL installation.
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If you install Single Sign-On with an external Microsoft SQL Server database, using a static port, and you have a firewall between Single Sign-On and the external database, you must open a static port on the firewall to communicate between Single Sign-On and the database. For example, to do this in Windows Server 2008, you can add a static port in the Windows Firewall Control Panel.