The ITP/MDK Repository uses a database to store all documents it contains. This database can be any multi-user-database that can be accessed and controlled with ODBC. The ITP/MDK Repository configures the database during installation. All you have to do is provide an empty database and a data source to connect to. Use the DBMS of choice to create a new database. Note its name and location; you will need it to create a Data Source Name.
Before installation, make sure that the account that will be used by the ITP/MDK Repository Server to access the database has owner rights to this database. This is necessary for the ITP/MDK Repository to be able to configure it. After installation, the rights of this user account may be reduced to 'normal' read and write.
Before performing an upgrade on an existing installation, you need to make a backup of the database. Upgrading may involve conversions that make it impossible to run the previous version of the software on it, in case you want to revert to that version or if anything goes wrong during the upgrade process. Also make sure that the database has enough disk space to grow, and - because of the conversions - that there is plenty room for the transaction log.
Warning
Please be aware that the database attached to ITP/MDK Repository contains important production data. Make sure that it is backed up on a regular basis.