We have spent a lot of time on our Entity Framework provider over the past 18 months or so. There is a sample EF provider from Microsoft that illustrates basic points, and if you look at all the open source databases they pretty much all used the default code in their implementations. But what if that sample code doesn’t implement something? Or if it is just plain wrong? I have to tell you we didn’t expect the results we got from this test at all. We expected that we probably had some room for improvement and that SQL Server would ace all the tests. Didn’t turn out that way.