Re: Mixing OO and DB

Dmitry A. Kazakov wrote:
> mAsterdam wrote:

>> Dmitry A. Kazakov wrote:
>>> mAsterdam wrote:
>>>> Dmitry A. Kazakov wrote:
>>>>> mAsterdam wrote:
>>>>>
>>>>>> In your extension, you appear to map your slaves to data.
>>>>>> Slaves behave, objects do. Data doesn't.
>>>>> If data did not behave how would it be possible to use data?
>>>> Being active is not, as your question presupposes,
>>>> a prerequisite to being used.
>>> No, I didn't meant that. Behavior is independent on who acts on whom.
>>> Consider it as a list of all things you could ever do with data.
>> It is not clear what you are asking with
>> "If data did not behave how would it be possible to use data?"
>> Please rephrase.

So what is it you are asking? This doesn't even look like a question. Should I unsnip? Remember that this is about what of objects and data is the better map to slaves in your metaphor extension.

Your snipping style is not nice to deal with.

Dmitry, why are you engaging in this thread?

>>> But why is recording essential? 
>> To facilitate the sharing of observations.

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.
Now there may be something sensible here, but without something of substance I have no way of telling. Seen as a proposal for additional shared primitives, add "0. To share." and for now forget about 2, 4 and 5.

> Isn't it a bit too much in order to define an allegedly fundamental thing
> called data?
>
> This question is only relevant if you are going to define 1-5 within your
> formal system, provided that were possible.

'your'? No.

Without agreed upon denotation it is just gibberish. You do not accept that there is data, but you do appear to have enough basis to start formalizing.
Which primitive elements does your formal system have?

> In case it rather falls under
> the category of meaning (=hand waving), then that is exactly
> same trick I used in my definition.

I am trying to uncover, not to cover up.

> I just said that in the formal system there are
> values with some semantics attached to, which (semantics) lies outside that
> system. Call it recording, encoding, observation, sharing whatsoever. All
> this is irrelevant to what we are going to do with data.
>

>>> Or to put it otherwise, can you consider unrecorded,
>>> not memorized data? 
>> No.

Are you suggesting π is data?

>>> 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.

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 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.

> Pi is Pi and retains all its property
> independently on where and how you write it (or not). Let's declare F = D
> and forget about R.

For now - ok.

> (BTW, some of DB people regularly posting to comp.object vehemently denied
> that DB is about persistency. Could you clarify it?)

No, not at this point. This is best left to a thread on its own.

Disclosure: I have in the past vehemently denied that DB is about persistency, and I have yet to see a coherent argument that it would be. Assume for now it is a belief I turned to after experiencing the way the smalltalk system image works and Rumbaugh's remarks on persistency.

>>> 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.

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.

> 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.

>>>>> (The type of values describes the behavior of data.)]
>>>> How? I don't understand what you are saying here -
>>>> this may be a language thing, though.
>>>> An example might clarify.
>>> Consider the value 1. It has no behavior (and no use) so long you don't
>>> tell us its type. It you say that 1 is an integer, then its behavior will
>>> include "has negative inverse." If the type is Positive, then the behavior
>>> will be "no negative inverse", "can be squared in R" etc.
>> Is this what you mean: All operations for which the set is closed?

>> If so - how is this behaviour of the data itself?

requote:
 >>>>> (The type of values describes the behavior of data.)]

>>> (Behavior does not presume anything like tiny cogwheels hidden inside 1.
>>> The cogwheels are rather big and all outside (:-))
>>>
>>>>> If the ultimate goal is same, then managing the thing called data is mere
>>>>> one possible thread of the process.
>>>> That does not follow.
>>>> Furthermore: after the process stops, the data remains.
>>> Really? You wrote just above:
>>>
>>> "it only makes sense to talk about data when the medium on
>>> which they are recorded is readable by some mechanism to
>>> achieve electronic representation, but that is not inherent
>>> to data."
>>>
>>> Which is all true. So let you have a medium without a process that can read
>>> it, what did remain of data? It what sense do data remain? As a possibility
>>> to start a process by some other process which still runs? Consider it on
>>> the example with 1.
>> In that sense all phonographs are part of the same process.
>> It's process, Jim, but not as we know it. Define process.

Don't.

> I wanted to know how do you want to distinguish "readable" and "unreadable
> data." I concede it was a leading question. The suggested answer is: if the
> thing was ever readable, it will ever be. You can always repeat the things
> you did once in some equivalent way, at least in mathematics you can.

Is it fun?

--
What you see depends on where you stand.