It would be useful if I could define a symbol in a database connection.

I would then expect that I'd be able to define either conditional extension methods in the "My Extensions.linq" file, which would then be conditionally built based on the database I'm connecting to (and thus could potentially reference/use the types from that connection).

An alternative/secondary thought - is a way of linking/specify a base query (basically just a way of ensuring @load is done) for any a db. That way any time I'd start a new linq query, it would either automatically add the @load line - or better yet, just have it automatically loaded in the background.