You can keep the same database schemas as earlier version instead of building a whole new one as long as you are planning to use the same DB (i.e. as an example, Oracle to Oracle but not Oracle to SQL Server).
You would be able to upgrade the schema, provided the user has the DBA privileges. This is called an in-place upgrade (Useful links are provided below). However, it’s always safe if you can take a backup of the DB before upgrading. When you do an in-place upgrade from DevTest 8.x or 9.x, the schema of the Enterprise Dashboard and the Registry database is updated and the existing data is maintained. You do not need to create a new database.