Re: Question on Structuring Product Attributes

On 2013-09-30, Derek Asirvadem <derek.asirvadem_at_gmail.com> wrote:
> On Monday, 18 February 2013 09:09:15 UTC+11, Eric wrote:

>> On 2013-02-17, Rob <..._at_gmail.com> wrote:
>>> On Saturday, February 16, 2013 4:20:01 PM UTC-7, paul c wrote:
>>>> On 14/02/2013 8:03 PM, James K. Lowden wrote:
>>>>> SQL was intended, I'm sure you agree, to be a language for deriving
>>>>> logical inferences.
>>>> [omitted text].
>> 
>> [more omitted text]
>> 
>>> Database technology has come a long way since the 1970s when SQL
>>> was initially specified, and relational DBMSs do alot more than
>>> report-writing. But to suggest that in the 1970s, the authors were
>>> interested in "logical inference" requires great poetic license compared
>>> to "replacing the report-writer capabilities of IMS", and feels like
>>> history rewritten.
>> 
>> To quote from Codd[1970]:
>> 
>>    "The adoption of a relational model of data, as described above,
>>     permits the development of a universal data sublanguage based on an
>>     applied predicate calculus. A firstorder predicate calculus suffices
>>     if the collection of relations is in normal form."
>> 
>> I rather think there is a connection between "predicate calculus" and
>> "logical inference", yes? So perhaps they should have been interested.
>

James said that SQL was intended to be a language for deriving logical inferences.

Rob said that saying this required "great poetic license".

I suggested that there is evidence to the contrary.

Where is the absurdity?

> Rob's point (as I see it) is that the asylum dwellers rewrite history,
> as they often do. Charging either the System R team, or the Sequel Team,
> or the SQL Committee (of old, before they were subverted), with having
> missing something that is relevant today, which was not a criterion in
> the 1970's, is simply dishonest.

You are making this up (and most of the rest of it) to support your own rather strange viewpoint.

snip ><

> Those who demand that the physical implementation must be limited to
> the limitations of the abstract, are lunatics.

The physical layer can do whatever the hell it likes, as long as it can produce correct results efficiently enough. However it is supposed to have an interface limited to the abstract model being supported (in this case, Relational Theory). There are two levels here, and those who cannot distinguish them are very wrong. This does not imply lunacy. Unfortunately you seem to be one of those who fails to make the distinction.

snip ><

> But 30 years after the null problem was resolved, ...

So tell me, in as few sentences as possible, what *you* think the Null Problem is.

While you are at it, tell me what Oracle "features" show that it can "do the Null Problem Really Well".

And finally, people can disagree with you, and even be wrong in doing so, without being lunatics, or insane, or abnormal.

Eric

-- 
ms fnd in a lbry