Which is more flexible in regards to database changes, EF 4 or Linq to SQL

Reading about both Linq to SQL and Entity Framework I have developed the impression that EF is more suitable for apps that get data from multiple data sources.

But as I am reading about MVC2 models I see an example where EF is more loosely coupled with your data model.

If I have to add or remove some columns from a table then what is involved in开发者_开发百科 updating my model or DAL with each of these implementations?

EF4 is the way to go. The mappings are no longer completely volatile so you can refresh them with database changes instead of recreating them. Linq to SQL and EF1 are more volatile.