Hi

I want to do a Website for an Insurance Company that has a large Database.I think that I should use Classes (Business Logic Layer) to accomplish this project.It's not going to be a simple task because there is lot of Fields and Calculations.

What do you recommand me to do?What Architecture should I use?Using BLL will fasten the application or there is no relation between classes and speed?

Do you have some sample code or Project in the Insurance field?

Any idea

thanks 

Using classes (Domain Driven Approach) won't necessarily speed the application up.  In fact it may well add some overhead as data is passed from one object to another through layers.  Architecture is generally driven partly by theory (doctrine, even) and partly by the requirement for flexibility and some maintenance/code organisation considerations.  It has little or no part to play in perfomance considerations.  Performance is driven mainly by how you apply ADO.NET to the application, regardless of the architecture.

As soon as some people see "Insurance Company" and "Large Database", they automatically think Custom Business Objects.  This may indeed be the best approach for you for this particular application, but the truth is, there is no definitively correct answer.

Here's some reading for you:

http://west-wind.com/weblog/posts/146.aspx
http://msdn.microsoft.com/msdnmag/issues/05/01/ASPNETPerformance/
http://weblogs.asp.net/fbouma/archive/2006/08/23/Essay_3A00_-The-Database-Model-is-the-Domain-Model.aspx
http://davidhayden.com/blog/dave/archive/2004/04/10/209.aspx