On the Robert Bruckner’s blog i found an intressting article about some changes Reporting 2008, SQL Server 2008 Reporting Services (SSRS 2008) features an on-demand report processing engine. This on-demand architecture has a number of key advantages over the processing engine design that existed in previous major releases. The most significant benefits are vast improvements to report engine scalability and performance (you can read a bit more about it here). Because of this fundamental change from previous versions, there are some specific design patterns that have changed. This post is a discussion of one scenario that, due to the new processing engine, requires a different design pattern in 2008 than was required in 2005 and 2000.
Using Group Variables in Reporting Services 2008 for Custom Aggregation
Read the entire atricle here.