Re: Sixth normal form
From: Bruce C. Baker <bcb_at_undisclosedlocation.net>
Date: Wed, 1 Aug 2007 22:01:33 -0500
Message-ID: <XNbsi.18844$rH6.6661_at_newsfe22.lga>
>> "paul c" <toledobythesea_at_oohay.ac> wrote in message
>> news:xV5si.22613$rX4.14717_at_pd7urf2no...
>>
>>>Brian Selzer wrote:
>>>...
>>>
>>>>It's somewhat unrelated, ...
>>>
>>>I was with you up 'til the first comma in the last paragraph. It sure
>>>doesn't have to do with redundancy. First there were rigid keys, then
>>>contingent keys, now we have immune keys. Newcomers please note - don't
>>>believe this mumbo-jumbo, it is all undefined mysticism, as is the term
>>>"key update".
>>>
>>
>>
>> Are you saying that Codd's use of "key update" in his definitive1970
>> paper was also mumbo-jumbo?
>> ...
>> Isn't it strange that people who can't come up with a solid argument
>> resort to misrepresentation, nitpicking over terminology, and outright
>> derision. Often they end up with their foot in their mouth.
>> ...
>>
>>>Also, I would like to know if anybody has ever invented a relational
>>>algebra or calculus that supports "update". AFAIK, update is either a
>>>system colloquial, environmental or a language, say SQL, term. Yeah, I
>>>know people say "update" a tuple et cetera and I think that's okay if it
>>>is agreed and understood just what exactly the system or dbms they have
>>>in mind is going to do about the "update". In the recent threads, I
>>>don't and I'm pretty sure we don't either.
>>>
>>
>>
>> It should be obvious that relational algebra and calculus are meant for
>> queries, not updates. Unlike the operators of relational algebra,
>> neither insert, update, nor delete returns a result. Nor does relational
>> assignment. More importantly, the algebra and the calculus involve a
>> single database value (set of relation values), a snapshot of reality if
>> you prefer. An update operator (as D&D call them) involves two snapshots
>> of reality, and truth in one does not imply truth in the other.
>>
>> Before you make a complete fool of yourself, I suggest you read Codd's
>> 1990 book. You should be able to find it online now. I did. I can't
>> remember where, though.
>> ...
Date: Wed, 1 Aug 2007 22:01:33 -0500
Message-ID: <XNbsi.18844$rH6.6661_at_newsfe22.lga>
"paul c" <toledobythesea_at_oohay.ac> wrote in message news:ZLbsi.23504$fJ5.6912_at_pd7urf1no...
> Brian Selzer wrote:
>> "paul c" <toledobythesea_at_oohay.ac> wrote in message
>> news:xV5si.22613$rX4.14717_at_pd7urf2no...
>>
>>>Brian Selzer wrote:
>>>...
>>>
>>>>It's somewhat unrelated, ...
>>>
>>>I was with you up 'til the first comma in the last paragraph. It sure
>>>doesn't have to do with redundancy. First there were rigid keys, then
>>>contingent keys, now we have immune keys. Newcomers please note - don't
>>>believe this mumbo-jumbo, it is all undefined mysticism, as is the term
>>>"key update".
>>>
>>
>>
>> Are you saying that Codd's use of "key update" in his definitive1970
>> paper was also mumbo-jumbo?
>> ...
> > Yes. > >
>> Isn't it strange that people who can't come up with a solid argument
>> resort to misrepresentation, nitpicking over terminology, and outright
>> derision. Often they end up with their foot in their mouth.
>> ...
> > No, it isn't strange to me, I see it all the time. >
>>
>>>Also, I would like to know if anybody has ever invented a relational
>>>algebra or calculus that supports "update". AFAIK, update is either a
>>>system colloquial, environmental or a language, say SQL, term. Yeah, I
>>>know people say "update" a tuple et cetera and I think that's okay if it
>>>is agreed and understood just what exactly the system or dbms they have
>>>in mind is going to do about the "update". In the recent threads, I
>>>don't and I'm pretty sure we don't either.
>>>
>>
>>
>> It should be obvious that relational algebra and calculus are meant for
>> queries, not updates. Unlike the operators of relational algebra,
>> neither insert, update, nor delete returns a result. Nor does relational
>> assignment. More importantly, the algebra and the calculus involve a
>> single database value (set of relation values), a snapshot of reality if
>> you prefer. An update operator (as D&D call them) involves two snapshots
>> of reality, and truth in one does not imply truth in the other.
>>
>> Before you make a complete fool of yourself, I suggest you read Codd's
>> 1990 book. You should be able to find it online now. I did. I can't
>> remember where, though.
>> ...
> > Let me know if you remember. A salesman stole mine. > > p
You can find the .pdf at the ACM Digital Library;
But it'd probably be cheaper in the long run to buy a copy from Amazon
http://www.amazon.com/gp/offer-listing/0201141922/ref=dp_olp_2/104-9019283-7102314
or Abebooks
http://www.abebooks.com/servlet/SearchResults?tn=relational&sts=t&an=codd&y=0&x=0 Received on Thu Aug 02 2007 - 05:01:33 CEST