Re: Nearest Common Ancestor Report (XDb1's $1000 Challenge)

From: Neo <neo55592_at_hotmail.com>
Date: 8 Jun 2004 14:39:43 -0700
Message-ID: <4b45d3ad.0406081339.9a18f97_at_posting.google.com>


> Neo should have been more clear in *his" definition of normalized, etc.

In the most general sense, normalization is the process of eliminating or removing redundancy. Within the context of a db, normalization is the process of eliminating or removing redundancy by replacing redundant data with an data-independent links/refs to the one and only original. Within the context of a db, multiple links/refs are not considered redundant data because:

  1. they are independent of the data being modelled.
  2. they are or should be hidden/inaccessible/transparent to the user.

I have stated similarly before. Below is a copy from Quote for 05/07/2004 at www.dbdebunk.com/page/page/857323.htm

Q: It's not clear to me you know what "normalized" means. Can you be specific about what normalization rules you are referring to? In what way is my schema not normalized?
A: Normalization: The process of replacing duplicates things with a reference to the original thing. For example, given "john isa person" and "john obeys army", one observes that the "john" in the second sentence is a duplicate of "john" in the first sentence. Using the means provided by your system, the second sentence should be stored as "->john obeys army". Another example, given "bob" one observes that the second "b" is a duplicate of the first "b" and therefore should be normalized as "bo->b". I don't want you to normalize this far [this exclusions was for a prior challenge], even though Ex076 is. The exact method of normalization and to what extent is practical is dependent
on the data model and its implementation.

--Neo, comp.databases.theory Received on Tue Jun 08 2004 - 23:39:43 CEST

Original text of this message