At my new company, they keep all data associated with the data warehouse, including import, staging, audit, dimension and fact tables, together in the same physical database.

I've been a database developer for a number of years now and this consolidation of function and form seems counter to everything I know.

It seems to make security, backup/restore and performance management issues more manually intensive.

Is this something that is done in the industry? Are there substantial reasons for doing or not doing it?

The platform is Netezza. The size is in terabytes, hundreds of millions of rows.

What I'm looking to get from answers to this question is a solid understanding of how right or wrong this path is. From your experience, what are the issues I should be focused on arguing if this is a path that will cause trouble for us down the road. If it is no big deal, then I'd like to know that as well.