Synchronize uses a central database containing calendaring information for the users it serves. As the number of users grows, the size of and traffic to the database grows in a corresponding fashion. Eventually, the database may be so large as to cause a performance bottleneck. For example, while support for 500 to 1,000 users in a single database may be feasible, support for 5,000 users is not. To deal with such issues of scale, as well as administration requirements within an organization, the Synchronize 2.0 release supports multiple distributed databases. Multiple Synchronize databases can exist on different hosts or on the same host.