Re: Objects and Relations
Date: 14 Feb 2007 13:43:18 -0800
On 14 fév, 21:39, "Roy Hann" <specia..._at_processed.almost.meat> wrote:
> "Cimode" <cim..._at_hotmail.com> wrote in message
> On 14 fév, 17:41, "Roy Hann" <specia..._at_processed.almost.meat> wrote:
> > Indeed. I personally believe that they are *necessarily* used because
> > there is no such thing as a natural key in nature.
> I am inclined to regard the data as the testimony of the users about the
> real world.
I understand your point. If you don't mind, I propose to replace *testimony* by *description* a term that more domain neutral and that seems safer candidate for generalization of reasonning.
> The keys that exist about which the users can say things are
> ultimately synthetic as you say, but they are pre-existing in the real
I am curious about that last sentence. Would you mind telling me which *pre existing keys* are you thinking of ? And most of all what constitutes the criteria which makes it pre existing ?
> The surrogates that we generate in the software during the process
> of recording the testimony are surrogates that spring into existence *after*
> the user assesses the real world and forms his testimony. Therefore they
> cannot have anything to do with the real world. They *are* different, if no
> more synthetic, and they are not strictly necessary--merely convenient.
I understand. Thank you for this description.
> > In my perspective,
> > a natural key is nothing but a socially accepted surrogate key.
> I agree, but a basic reason it is capable of being socially accepted is that
> it is pre-existing in the real world of interest.
Mmm...I am not convinced that the acceptance necessarily implies preexistence of some natural key. For instance, practicality of use and/or familiarity are sufficient self sustaining causes for explaining acceptance.
> > Such process may explain the
> > individual unease feeling when associating a thing with the
> > designation that is assigned to it.
> My unease is twofold: to generate surrogates that don't have unintended and
> unacceptable implementation consequences requires a lot of quite clever
> machinery the expense of which cannot always be justified, and second,
> "surrogates" are often introduced in the absence of a reliable natural key
> rather than as a surrogate for a naturual (socially accepted) key, masking
> possible contradictions and errors behind spurious uniqueness.
I undesrtand the nature of your dilemna but I believe such dilemna comes from the fact that your reasonning assumes the preceding existence of some natural key. I do believe on the contrary that such precedence can not be established for a simple reason: there is no such thing as a natural key in nature (none that I have found in a fundamental perspective).
At some point, any natural key was a surrogate key. In other words, I do perceive the surrogate key as the chicken not the egg. I also consider that there is no such thing as an spontaneously generated egg in nature. It seems to be a matter of perspective. Accepting such perspective may help alleviate your dilemna. Received on Wed Feb 14 2007 - 22:43:18 CET