[Koha] KOHA for Archives

Hello I am working with Koha in Portugal and very soon I will send staff translation which is being finished. I would like to ask and sugest an improvement for Koha allowing to work simultaneous with several databases (Koha1, Koha2, etc.) Instead to have just one MySQL database. How can we select an alternative database with the same framework? If we can do it I will develop a MARC framework for Archives and then we could cope both with libraries and archives. The only thing is to change framework and switch between databases. Best regards, Rafael Antonio