Developers who need the full features of SQL Server 2008 R2 Enterprise Edition for use in a non-production environment may find SQL Server 2008 R2 Developer Edition the right tool for the job.It supports the standard hub-and-spoke data warehouse architecture. SQL Server 2008 R2 Parallel Data Warehouse Edition provides an appliance-based solution for highly scalable data warehouse applications.Datacenter edition provides access to SQL Server's multiserver administration tools and allows the use of unlimited memory. SQL Server 2008 R2 Datacenter Edition supports up to 256 logical processors and provides high-end scalability.It's also more expensive than it was before but has discounted options for 25 users. It previously supported unlimited processors but is now capped at eight CPUs. SQL Server 2008 Enterprise Edition is now more limited than in the past.Standard Edition 2005 introduces database mirroring and integration services. It can handle up to four CPUs with an unlimited amount of RAM. The workhorse SQL Server 2008 R2 Standard Edition remains the staple of the product line for serious database applications.It offers limited replication capabilities as well. Workgroup edition maxes out at two CPUs with 3 GB of RAM and allows for most of the functionality you’d expect from a server-based relational database. SQL Server 2008 R2 Workgroup is billed as a “small business SQL Server” and it offers an impressive array of functionality for a price tag per processor or available under a 5-user license.
It’s a great tool for developing and testing applications and extremely small implementations, but that’s about as far as you can run with it. It remains free and retains the limitations of MSDE with respect to client connections and performance.