Re: What does this NULL mean?

"Alfredo Novoa" <alfredo_novoa_at_hotmail.com> wrote in message news:1134574071.843808.11170_at_g14g2000cwa.googlegroups.com...
> "mountain man" <hobbit_at_southern_seaweed.com.op> wrote
>
>>Theorists like Date who think the null should be rationalised
>>out of existence have no demonstrated understanding of the
>>database change management environment,
>
> Database design maintenance has nothing in special.

Well then neither does the original database design. One is just as critical as the other.

>We should be able
> to manage the schema applying the usual relational operators on the
> catalog relvars, besides the shorthands like: drop Table, etc.

Change management is able to be managed. Yes.

>> and specifically
>>the management of schema evolution and its consequences
>>in regard to the generation of nulls.
>
> They are completely independent issues. Nulls are a mistake

That is simply your opinion. Nulls being a mistake is Date's mistake, and fortunately Codd never agreed with Date.

> and schema
> maintenance is something elemental and straighforward.

It obviously depends upon the actual maintenance being conducted, and simplistic sayings like the one above should be ignored except by poets.

>>Change management or schema evolution is not adequately
>>addressed by Date et al,
>
> It is sufficiently addressed, but it is so trivial that there is little
> to say about it.

In that case, out with the trivialised summary of schema evolution. You have the floor. Please outline what Date has said about this issue.

>> however by the time they set forth
>>the processes covered under this subject, it will become very
>>apparent that the NULL will never be rationalised away, and
>>it is better to therefore appropriately manage its identification,
>>its existence and its resolution interactively.
>
> Plain nonsenses.

I will defer response on this pluralistic phrase until you have answered the question above ---- if you are able to do so.

-- 
Pete Brown
IT Managers & Engineers
Falls Creek
Australia
www.mountainman.com.au/software