I have spoken about virtualization and the different types of virtualization. Which includes OS zones, application server domains, database schemas, VLANS and other approaches. Another approach is to create a virtually federated database in the cloud. DBSpaces is a company that has a technology to created a virtually federated database in the cloud. DBSpaces is a Virtual Database technology that allows an organisation thru a single Virtual Database access multiple data sources (or database spaces) in real-time. Additionally dbSpaces can be configured to access an organisations data internally using a remote gateway so that their dbSpace is seamless across the Public and Private cloud.