A Technical Blog, originally posted at http://www.adamtibi.net/07-2012/using-c-sharp-net-user-defined-functions-udf-in-excel
Exposing .NET functions to be consumed as Excel functions, otherwise known in Excel as "User Defined Functions" . Those .NET exposed functions can be easily used from Excel's cells. This article presents two ways to achieve this and the pros and cons of each.
Top 10 steps to optimize data access in SQL Server: Part III (Apply advanced indexing and denormalization)