Re: Storing data and code in a Db with LISP-like interface

From: JOG <jog_at_cs.nott.ac.uk>
Date: 16 Apr 2006 05:08:24 -0700
Message-ID: <1145189304.593238.68080_at_g10g2000cwb.googlegroups.com>


topmind wrote:
> Nulls are a vendor-specific idea, not inherent to relational.

While I agree with much of your post, nulls now appear to me to be essential to the relational model (whatever their rights and wrongs). If one fully normalizes a database then it is likely a join will require the use of null to pad the resulting virtual relation. Just because these relations are not persisted on disk, makes them no less 'relations' in the sense of Codd's algebra. As such i am currently struggling with how one can be against nulls (as per Date's perfectly justified view) but pro-RM from a completely theoretical standpoint. Received on Sun Apr 16 2006 - 14:08:24 CEST

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