Re: Mixing OO and DB

From: Dmitry A. Kazakov <mailbox_at_dmitry-kazakov.de>
Date: Fri, 15 Feb 2008 15:43:39 +0100
Message-ID: <i9fdr27mg3gd.1rr2rztvlsczt$.dlg_at_40tude.net>

On Fri, 15 Feb 2008 00:41:37 +0100, mAsterdam wrote:

> Dmitry A. Kazakov wrote:

>> mAsterdam wrote:
>> 
>> But you certainly should have a mental picture
>> where "data" plays some role. 

>
> 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.

Maybe what you are using "data" for, could be common.

>> 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?
>> 
>> Value, type, variable, operation.

>
> 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?

Date's definitions were OK for values and types. Any value has exactly one type. Variables map the computational states onto values. I think it would be more or less acceptable for anybody. Much more difficult is to agree on subtype and class. Class is a set of types. Subtype is a type relation of some properties (transitive, reflexive etc), and so on.  

>>>> 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 ð is data?
>> 
>> Yes. But you can take some P(pi)=true instead.

>
> Or R(P(ð)) - 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.

Then I see no disagreement anymore. Is all that rant going on for years between c.d.t and c.o just about what to feed to the beast?

[ BTW, it was exactly the point I made in my first post to this thread. It is not about theory it is about selling stuff = making sense outside the system = getting money out of customers. (:-)) ]

>>>>>> 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.
>> 
>> (A side question, in "R is just 1", were "just 1" data or fact?)

>
> 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.

In order to be able say, that the property (or whatever) "is 1" has to be data (to be any "useful", using your terms). Thus it itself needs this property, which constitutes an infinite recursion.

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

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

In other words being recorded / data is incomputable.

>> 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.

"To support" needs to be defined. If you mere mean self-consistency or Turing-completeness, then it is OK. If you mean something finer than that, you have to say what. Anyway it would be not "I want data, else there is no common ground." It would be about the structure of the formal system which you wished deploy for what you call data. (Maybe, I could to do it as well, but for something having a different name.)

>> 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.

In both cases you constrain a process. So if complementary of views was your point, I think it is invalid. Further if you want to deal with D in IDO, you need a language to describe D. That is a formal system, a process. I.e. you cannot abstract D out of some processes, generating, carrying, understanding data.

>>>> 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.
>> 
>> OK, I am back on vacation. How are you going to formalize something which
>> cannot be formalized? (:-))

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

Neither I am. But shared can be also a method of understanding. You consider understanding as a premise (data (:-)). Do it rather as process (behavior (:-)).

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

Received on Fri Feb 15 2008 - 15:43:39 CET