Re: Foreign key in Oracle Sql

David Cressey wrote:

> I'd like to respond to your request for TECHNICAL reasons,
> without wasting too much time on the fray part of it.

Thanks for the excellent in-depth discussion of how the relation kernel deals with NULL values. However, perhaps I'm just dense here, but I wasn't able to discern the technical reason you couldn't implement a runtime switch to enable this sort of thing to change going forward.

As an example of what I consider a simple solution, you have a per-schema flag that indicates whether that particular schema should use old-null-semantics, or new-null-semantics. If a schema has the new-null-semantics flag, when an actual NULL is requested, you will get a pair of bytes, each with the value zero. Just like the concept of a "minus zero", this won't make any sense when treated as anything other than NULL.

(Note: Merits of my particular technical solution aside. I'm not in the habit of writing database engines. That's why I'm asking -- to see what it is that I'm missing in my awareness that would stop there from being a technical answer.) Received on Fri Jan 21 2005 - 17:34:41 CET