Regarding the "central/shared" database: We have scripts that do the nightly build process, and do a database install to a shared server, with the extra twist that the build number is part of the database name (as suffix). This central database can be used by a developer who doesn't want/need to install each build locally every day. We don't view the central install as "inviolate", they get thrown away after a while; but they let a developer compare a query on their environment versus "how did it work in the build yesterday/week ago/etc."