There a fascinating discussion going on at Tim Sneath's blog about the functionality of the business layer moving to compiled stored procedures in Yukon. At least in my project, we have been doing that very thing and struggled with the n-Tier issue as a result. In our case, the database is Oracle 8i, and the application is/was ASP, which we are now converting to .Net. We have some very complex business logic encapsulated in PL/SQL stored procedures. There were two concrete reasons for the decision:
- The amount of data that would need to be transferred was huge.
- Oracle is more efficient than ASP code at many of the operations involved.
With ADO.Net, some of the ineffieciency may be addressed, but the database is designed for efficiency at certain operations that ADO.Net won't be able to match.
We did not need to approach this from a scalability issue, as the app receives hundreds of hits per hour, not thousands or more. I still think it will scale OK as your business objects will have much shorter life spans and you can still pool and queue database connection objects if needed due to long-running stored procedures.