What is the best data access paradigm for scalability?

Question

There are so many different options coming out of microsoft for data access. Which one is the best for scalable apps?

Linq

Should we be using Linq? It certainly seems easy but if you know your SQL does it really help. Also I hear that you can't run Async queries in ASP.NET using Linq. Therefore I wonder if it is really scalable? Are there any really big sites using Linq (With the possible exception of stackoverflow).

Entity Framework

Don't hear so much razzmatazz about the Entity Framework. Seems closer to the Object model I'm familure with.

Astoria/Dynamic Data

Should we be exposing our data as a service?

I'm pretty confused and thats before I get into the other ORM products like NHibernate. Any ideas or wisdom on which is better?

Answer 1

I would recommend either NHibernate or Entity Framework. For large sites, I'd use ADO.NET Data Services. I wouldn't do anything large with LINQ to SQL. I think Stack Overflow might end up with some interesting scale problems being 2-tier rather than 3-tier, and they'll also have some trouble refactoring as the physical aspects of the database change and those changes ripple throughout the code. Just a thought.