Re: Proposal: 6NF
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 06 Oct 2006 12:44:01 GMT
Message-ID: <lcsVg.1215$cz.17835_at_ursa-nb00s0.nbnet.nb.ca>
>>>Note: Brian Selzer has carried this point further in another subthread.
>>
>>You are begging the question.
Date: Fri, 06 Oct 2006 12:44:01 GMT
Message-ID: <lcsVg.1215$cz.17835_at_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 - 14:44:01 CEST