Re: All hail Neo!

On 26 Apr 2006 00:55:22 -0700, "Marshall Spight" <marshall.spight_at_gmail.com> wrote:

>Frank Hamersley wrote:
>>
>> I can cope with that - I would have no problem being forced to write
>>
>> "select avg(age) from table where age is not null"
>>
>> to get the crappy statistic that it is if the user demanded it.
>
>I dunno. If you have a whole lot of people and most of them
>have their ages filled in and a few don't, are you ever going
>to want to ask, "what is the average age", since the answer
>will always be "unknown." Doesn't seem much use to me.
>If you want to know if any of them are unknown, you could
>ask that specifically. But if you want to know the average
>age, then you want to know the average of the data you have;
>you're not asking about the data you don't have because
>you don't have it. The only useful query in there is "give
>me the average age for the data I have"; why should we
>make the way you ask for that longer winded than other,
>never-useful queries?
>
>And how "crappy" is that statistic anyway? Probably not

     Obviously, we do not know.

>at all crappy. It's probably exactly what you want.

     Possibly, it is near the actual value. Since it is only a guess, who knows?

>The idea of null as something that taints everything it
>touches doesn't seem useful or practical to me.

     It is quite useful. It means you do not have enough data yet. If you are guessing, at least admit that you are doing so.

     Try filling out a tax return with one piece of data missing. Do you think that your government will go for "It's probably exactly what you want."?

Sincerely,

Gene Wirchenko Received on Wed Apr 26 2006 - 21:24:16 CEST