Re: Mixing OO and DB

Dmitry A. Kazakov wrote:
> mAsterdam wrote:
>

>> Dmitry, why are you engaging in this thread?

Heh. Same thing here.

>>>>> But why is recording essential? 
>>>> To facilitate the sharing of observations.
>>> So, we have now:
>>>
>>> 1. observations
>>> 2. entities (busy with sharing observations)
>>> 3. actions (state?) of sharing something (like observations)
>>> 4. identity (of "same" thing being shared/observed)
>>> 5. identity (of "different" entities observing "same" thing)
>> No we don't. You don't have anything here, because you reject the 
>> existence of data. Beyond some agreement on that any attempt at 
>> formalization of it is futile. You asked my opinion, you reflected it
>> against some of your preconceptions about what to formalize
>> and what not, and something comes out.

Is it necessary for both sides of the border to fully understand the formalisms en vogue at the other side? I don't think so. Your position - I trust you'll correct me if I'm wrong - is: there is no data, no other side, no border to cross.

> Let you to tried to formalize it. You would describe some properties
> and axioms about "data". You would also like to remove much of unnecessary
> and uncertain things (like 1-5 from there). What I tried to say is that
> after doing this, you could probably notice that you can remove "data" from
> your system without any loss...
>

>> Which primitive elements does your formal system have?

That looks rich enough to get somewhere.

Somewhat OT to this thread - just because I am curious: do you have a reference to definitions/descriptions of how these act together you consider worthwhile?

>>> Bad. It means that you have to formalize "memorize" in some quite tricky
>>> way. Honestly I don't know what could be the difference between "memorized
>>> Pi", "not-yet-memorized Pi", "once-memorized-but-forgotten-by-now Pi" and
>>> so on.
>> Are you suggesting π is data?

Or R(P(π)) - packaging a symbol/value doesn't make it data. In order to be data it should convey a fact, relevant in a sense outside the formal system, i.e. an observation, or the basis for a decision.

>>>>> May I translate data into a different
>>>>> representation and then erase the original record? 
>>>>> Will data still be there?
>>>> Iff it conveys the same facts as the original record, sure.
>>> OK, that means that data = facts + record medium of:
>>>
>>> D = (F, R)
>> Guessing about your notation as D denotes Data, F denotes Facts, R is 
>> the requirement that the fact is recorded, R is just 1.

It is the 'recorded' property of the fact. As you deny the existence of facts and data I don't see how this is relevant to you. (This /is/ accurate, right? I don't want to even /look/ like calling somebody an idgit in this thread - for polical correctness, of course :-)

>>> It also states that
>>>
>>> F1 = F2 => D1 = D2
>> Almost. Within a shared set of observations,
>>
>>   F₁=F₂ ⇔ D₁=D₂

>>> Why should I care about R, then? 
>> Why do you? I don't yet.

>> For now, I don't care about its internals,
>> just that it exists so we have a way to record facts.

By definition recorded (data) vs. maybe recorded maybe not (facts). D ⊆ F
(don't know if this covers partial recordings)

> And, equivalently, you cannot describe
> recording in terms of either data or facts.

Yep, that's the fate of primitives and semi-primitives.

[snip persistence]

>>>>> A formal system operates on data
>>>>> without any clue of the meaning of.
>>>> I think that is to crude.
>>>> The meaning itself is informal, hence inherently impossible to fully
>>>> access from within the formal system (I think we agree on that).
>>>> However, without meaning to associate it with, a formalism is useless.
>>> It is a tautology. You say that without meaning there is no meaning. 
>> No, though your rephrase is (a tautology).
>> I'll state it differently.
>>
>> Without shared, informal denotations, any formalism is useless crap.
>> I don't want it and you don't want it.

Indeed, but it is a proxy to it.
In C. Date's books it is called the external predicate.

> and uselessness is yet another thing.

Yes. A thing pertaining to the reason of the formal systems' existence.

> But I see no disagreement in the core issue:
> a formal system does not operate meanings.

I see no agreement to the core issue:
A formal system needs to support meaning to be useful.

> It is we who assign meanings to the inputs and outputs, and, at
> yet another level of understanding, judge about the formal system as a
> whole in terms of its usefulness, for example.

It is IPO vs. IDO (late 70's debate) all over:

Input values - Process - Output values: It does not matter what the input means, as long as the output is correctly processed from the input.

Input process - Data - Output process: The input process (datacapture) is to be constrained in order to prevent inconsistencies in the data. The output process (rendering) should be validated not to corrrupt meaning. "You have 01 vacation days left". Ouch - but just within the currently acceptable range.

>>> Yes, we cannot reason about meaning while staying 
>>> within the same formal system.
>>> Because you seem to bind data with a meaning (as I do), that immediately
>>> kicks the notion of data out of the formal system. So data do not exist
>>> there. Which is all my point! No data, nothing to worry about.
>> And the result is a hermetic system as useful as solipsism.
>> Have some fun there! I'm out waiting until you are bored of it.

Hey, I am not the one eager to formalize without a proper, shared, informal understanding.

--
What you see depends on where you stand.