Marcin,
Thank you for that info. But just to be clear, we are installing 6.12 to an existing 6.12 Database that is a copy of the production DB using the method described in KBA-35828. Will the installer not find the existing production DB in the same SQL instance and attempt to use it?
For example we will have DWSYSTEM and DWSYSTEM-TEST, DWDATA and DWDATA-TEST, etc. Will we be able to specify the correct DB at installation time?