Re: Nearest Common Ancestor Report (XDb1's $1000 Challenge)
From: Nick Landsberg <hukolau_at_NOSPAM.att.net>
Date: Wed, 09 Jun 2004 02:57:50 GMT
Message-ID: <O0vxc.30518$Gx4.20702_at_bgtnsc04-news.ops.worldnet.att.net>
>
>
> 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
Date: Wed, 09 Jun 2004 02:57:50 GMT
Message-ID: <O0vxc.30518$Gx4.20702_at_bgtnsc04-news.ops.worldnet.att.net>
Neo wrote:
>>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
While I am not a theorist, if I recall Codd's paper on the subject, there was the concept of "first normal form" (1NF).
He used it to be able to derive things like "third normal form" (3NF).
Granted that I am splitting hairs at this point (pour le bon chat, le bon rat), why is Codd's first normal form an unnaccaptable solution to the problem? You did say "mormalized" without any qualifiations didn't you? Originally? Not 3nf or 5nf or BCNF or XYZNF or anything like that. You didn't specifically define terms. Sorry, you lose.
-- "It is impossible to make anything foolproof because fools are so ingenious" - A. BlochReceived on Wed Jun 09 2004 - 04:57:50 CEST