The way that I've always seen it is: PRODUCTION - One server, one database. Right size the server to the database. Easy to implement one set of policies and procedures that meet the production requirements. Server/database downtime is easier to schedule. DEVELOPMENT/TEST/TRAINING - Stick them all on one box in different databases. Much more flexibility in policies and procedures. For downtime - just tell them it'll be down. They'll complain but the business won't suffer. Make sure that your have an SGA/Disk Csar who is responsible for allocating computer resources. I've never had any real problems with that.