Re: Proposal: 6NF

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 06 Oct 2006 12:44:01 GMT
Message-ID: <lcsVg.1215$cz.17835@ursa-nb00s0.nbnet.nb.ca>

David Cressey wrote:

> "Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message
> news:6M6Vg.656$cz.9617_at_ursa-nb00s0.nbnet.nb.ca...
> 

>>David Cressey wrote:
>>
>>
>>>"David Cressey" <dcressey_at_verizon.net> wrote in message
>>>news:F4uTg.998$rH1.633_at_trndny05...
>>>
>>>
>>>>First, let's find out where we all agree, then work our way towards

> 
> where
> 


>>>>there are different viewpoints.

>>>>

>>>>Here's a starter:  A schema in DKNF will have no nullable columns.

>>>

>>>I  got no answers to the first point, but I think we all agree.

>>>

>>>Here's the next point.

>>>

>>>An outer join between two relational tables will, in general,  produce a

>>>table with nullable columns.

>>>
>>>Note: Brian Selzer has carried this point further in another subthread.
>>
>>You are begging the question.

> 
> I'm not sure which question I'm begging.
> 
> Please note that I did NOT assert that outer join is a relational operation
> or that the result of an outer join is a relational table.

You assumed outer join involves NULL to conclude outer join involves NULL.

See: http://en.wikipedia.org/wiki/Begging_the_question Received on Fri Oct 06 2006 - 07:44:01 CDT