Our system runs on multiple data centers in different countries. We need to roll up values from tables into a warehouse. So we need a unique key for each record, ints of course not being an option.

Guids are too slow. (see: http://www.informit.com/articles/article.aspx?p=25862&rl=1 )

So we have a function that will return a unique key that doesn't have the same performace penalty (see same article for the generator).

Is there a way with version 2.5, SelfServicing, to tell the system to use this function as it's unique key generator instead of relying on @@Identy etc?

I can override every entity collections' EntityAdding function, but would rather have a way to specify it, perhaps with Dependency injection?

Thanks, Ian

If there is any chance you can use SQL 2005 instead of 2000, you may want to look at NEWSEQUENTIALID(). Still a GUID, but eliminates some of the concerns in the referenced article.

Do a Google search to see some of the pros and cons.

Maybe you just need to use a common base Validator to validate the entity before save, to call your method and set the Unique field.