Re: Proposal: 6NF

From: J M Davitt <jdavitt_at_aeneas.net>
Date: Tue, 03 Oct 2006 00:19:14 GMT
Message-ID: <60iUg.3585$Cq3.515_at_tornado.ohiordc.rr.com>


Brian Selzer wrote:
> "Cimode" <cimode_at_hotmail.com> wrote in message
> news:1159797534.237592.159150_at_e3g2000cwe.googlegroups.com...
>

>>Brian Selzer wrote:
>>
>>>"Roy Hann" <specially_at_processed.almost.meat> wrote in message
>>>news:P-Sdnd58Trp7GYLYnZ2dnUVZ8tGdnZ2d_at_pipex.net...
>>>
>>>>"David Portas" <REMOVE_BEFORE_REPLYING_dportas_at_acm.org> wrote in 
>>>>message
>>>>news:1159692483.421785.264660_at_c28g2000cwb.googlegroups.com...
>>>>
>>>>>Brian Selzer wrote:
>>>>>
>>>>>>The argument JOG made focused only on recording information, not
>>>>>>retrieving
>>>>>>it.  Why would anyone abandon a sound mechanism that can 
>>>>>>significantly
>>>>>>reduce the computing capacity required to answer a query?
>>>>>
>>>>>Because your argument is merely an assumption based on what some
>>>>>systems of today are capable of.
>>>>
>>>>It's worse.  His entire position is based on not knowing even what some 
>>>>of
>>>>today's products are already capable of.  For example, he seems unaware 
>>>>of
>>>>the role of the optimizer.
>>>>
>>>
>>>I understand fully the role of the optimizer.  That's one of my points. 
>>>If
>>>you arbitrarily split a table with a nullable column, then you're robbing
>>>the optimizer of possible execution plans.  It may make sense to split a
>>>table, for example, removing non-key columns that are seldom used in 
>>>queries
>>>into another table in order to boost the performance of all other 
>>>queries.
>>>The point I'm trying to make is that the decision should not be 
>>>arbitrary.
>>
>>Consequences of NULL uses goes far above he simple problem of
>>execution.  It hinders performance at all levels (response time,
>>concurrency) and introduces a very strong part of subjectivity in
>>interpretation of data presented to users.
>>

>
>
> I don't agree. Judicious use of NULL can improve performance, response
> time, and concurrency.

A wrong answer isn't always better because it cost less.

   In addition, when used correctly, no subjectivity is
> introduced. For every database schema with NULLable attributes, there is
> always an equivalent schema without.

Well, being the god* you seem to be, I won't doubt that solely because you said so.

  • Genius of Design

   Any subjectivity would therefore be
> independent of the database schema. On the other hand, arbitrary or
> incorrect use of NULL can cause all of the problems you describe.
>
>

>>>>Roy.
>>>>
>>

>
>
Received on Tue Oct 03 2006 - 02:19:14 CEST

Original text of this message