I just posted an article What does server side FOR XML return? (http://blogs.msdn.com/sqlprogrammability/articles/576095.aspx) which gives some details of the design and performance characteristics of various FOR XML flavors.

 

I also added links to XML whitepapers and publications on the design of XML features in Microsoft SQL Server 2005 to the links section of the main SQL Programmability & API Development Team Blog page (http://blogs.msdn.com/sqlprogrammability/default.aspx).

 

Best regards,

Eugene Kogan

Technical Lead

Microsoft SQL Server Relational Engine