I explain, typical DW scenario. The last n days are used a lot, the rest NEVER or RARELY... will I be able to compress that big and fat calldetail table for days older then 31 for example? seamlessly?
This can be done in SQL Server 2005 as well. What you need to do is creating at partitioned table, where the "old" data resides in a read-only filegroup. Both SQL Server 2005 and 2008 supports NTFS compression of read only databases and filegroups.