Re: FW: Surrogate keys (Was: enums)

Josh Berkus wrote:
> Why? I don't find this statement to be self-evident. Why would we have ON
> UPDATE CASCADE if keys didn't change sometimes?
>
Many times you will have references to a specific row from somewhere outside of your
database. Perhaps you have a federation of web services that collaborate or other arbitrary
URL's that contain the key.

It might be harder to create remote row sets, middle tier caches, and other similar
constructs if you cannot trust that the primary key is immutable. Such mechanisms often
trust that the primary key can be used to refetch the data and that it has been deleted if
it's no longer found.

> Anyway, my opinion on this, in detail, will be on the ITToolBox blog. You can
> argue with me there.
>
That will be interesting reading. I didn't find it (yet). Can you please post an URL here?

Regards,
Thomas Hallgren