Is it possible to mock, or create a facade, to replace a SQL Server database in-place, currently being used directly by a website via ADO.net, with a service (ideally WCF or other .NET technology)?
Example:
Consider an ASP.NET website with a lot of features which use SQL Server 2008 over ADO.NET. The SQL transactions involve many stored stored procedures, though there are some direct T-SQL transactions. It would be powerful to be able to replace the (singular) SQL server with a more scalable implementation, without having to re-implement the website features.
This could be a shim for ADO.NET, or an ODBC driver to a custom service framework, or something else. The "right" answer may seem to be "reimplement the website to use a more abstracted data interface", but let’s consider that the website code is immutable (though configuration could be altered).
Maybe simply provide an data access layer that specifies well designed interfaces. Your website will only ever have a handle on an interface, and you can use dependency injection/IoC to provide your concrete implementation of your interface on an as needs basis.
It’s not an “existing technology” as such, but probably just a prudent way forward in your design I’d suggest.