I don't see how performance could be improved by using an application solution. SQL is already set-based as can insert, update, and delete anything from the Xml you send in in one pass. CLR or any C# solution on the other hand will need to issue multiple statements to the database (and since you're talking about an application service - you also talking about multiple network passes back and forth between SQL Server). No, this would slow down performance drastically. You'd be surprised how efficient the Xml query engine is in SQL 2005 and up.