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Re: All hail Neo!

From: Frank Hamersley <terabitemightbe_at_bigpond.com>
Date: Thu, 27 Apr 2006 03:38:18 GMT
Message-ID: <K0X3g.17126$vy1.10724@news-server.bigpond.net.au>


Bob Badour wrote:
> Marshall Spight wrote:

>> Frank Hamersley wrote:
>>> Marshall Spight wrote:
>>>
>>>> The idea of null as something that taints everything it
>>>> touches doesn't seem useful or practical to me.
>>>
>>> I fully understand the sentiment however in cases like this I prefer
>>> arrangements that retain flexibility for the (awake) programmer and
>>> provide a form of simple clarity.
>>
>> I agree, however I think what I described better meets these
>> criteria than what you described! As far as flexibility goes,
>> you can always put a CASE statement around the value
>> if you need to.

I have prolly have made to Bobs killfile but for other readers benefit I will rebutt even if they lead to blind alleys.

> Since null reduces expressibility relative to the RM, the premise above
> is false. Having no ability to express an important concept is neither
> flexible nor powerful, and null reduces one's ability. Pretending that
> this has no practical consequence is intellectually dishonest.
>
> I can only surmise Frank uses some special sort of Orwellian logic. Not
> Orwellian in the sense that Orwell would ever use it himself, but in the
> sense of the so-called logic Orwell described so well. Frank's reasoning
> is fallacious as already established here.

And I reply that Bob only uses "normal" Orwellian conditioned reflex viz "stopping short, as though by instinct, at the threshold of any dangerous thought...and being bored or repelled by any train of thought which is capable of leading to a heretical direction."

A pity but ce la vie! BTW I claim touche!

>>> i.e. if there is one null the avg() is null.
>>
>> I can't ever imagine a situation where this would be useful
>> or desirable. Anyone?

>
> I will be kind and assume your lack of imagination results from imbibing
> too much of the elixir itself.
>
> Since when are correct answers neither useful nor desirable? Do you
> prefer your employees give you incorrect answers to avoid admitting when
> they do not know an answer?

How about when you ask for an estimate? Is that likely to be correct or incorrect?

>> Let's say I had a customer database with 1000 customers in
>> it, and I have the age of 999 of them, and one null.

>
> Let's suppose instead you are a direct marketer whose database records
> facts on 25 million customers. Let's further suppose your demographic
> information is incomplete based as it is on self-reported questionnaires.
>

[..] [BB is getting as voluminous as the other members of his killfile]

Happens all the time and will continue to happen, "fixing" SQL won't address the foibles of human behaviour.

> Let's say

>> I hire an analyst because I want to study some things about
>> my customer database. Maybe I want to do some TV advertising,
>> so I want to know some things about the demographics of my
>> customers. I ask the analyst, what is the average age of my
>> customer base, and what does each decile look like? The
>> analyst comes back later, and says, the average age of
>> our customer base is unknown. For each decile, there are
>> 100 people, and the average of each decile is unknown,
>> and the range of ages in each decile is unknown. I'm going
>> to fire that analyst and get a good one.

>
> As would I. He should say: "How do you want me to handle the unknown
> ages?" Or: "Only 1 age in your database was unknown. That will not have
> a significant impact on the following deciles, which I have rounded to
> the nearest year in any case:..."
>
>
>>> This simplistic approach means any stray nulls creeping into a dataset
>>> where none are expected will not go undetected if inadequately
>>> constrained queries are framed.
>>
>> I don't see this as an issue. The schema controls whether nulls
>> are allowed or not; if they are not allowed, they won't be there,
>> and if they are allowed, they are pretty much certain to be there.
>>
>> And again, if for some strange reason you want to query for
>> that, you can.

>
> But how do you ask it to deliver the correct average? Or the correct
> minimum? Maximum? Sum? Null simply prevents one from asking the
> question. Hence the illusion of power.

Refer my para 2 (Orwell) this post.

Cheers, Frank. Received on Wed Apr 26 2006 - 22:38:18 CDT

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