Re: Database design, Keys and some other things

Marshall Spight wrote:
> mAsterdam wrote:

>>Marshall Spight wrote:
>>The snipped questions weren't purely retorical.
>>They pointed in another direction.
>>Many interesting things happen at boundaries - but they
>>are interesting only to people who are interested.

>>What does exist oustide the minds of the users? This
>>relationship is a shared illusion. How did it come into being?

Putting them in one list doesn't make them of the same order. "Is there a God?" - off topic.
"What happens when you die?" - off topic (digression: except maybe that a database contains dead objects in the sense then as soon as they are in the database they stop behaving - food for another thread). "Is there an objective truth outside of my subjective perception?" - is of a different nature thought some refinement is necessary.

The design of a database is for a large part the creation of a shared illusion: let's put facts in a container. The predicates are the types of fact we are going to accept, the propositions the thruths we agree are relevant to our business. You won't get money from your ATM if you can't trick your bank into believing that it is you there, and that they have a good reason to let you have that money. They wil check some of their facts to establish that reason.

Or this: "I can't help you sir, you are not in the computer". An ICT worker deals in thruths, lies and semi-thruths.

> These questions are big, big questions, no doubt. However,
> what makes a question interesting to me is, to what extent
> can cogitation, observation, discussion, and experimentation
> lead to a better understanding. So these big, big questions
> are not in any way interesting. They are the philosophical
> equivalent of an infinite loop: fun to look at for a short
> time, but they quickly become boring, because no progress
> can be made on the problem.

I'm with you on avoiding those loops.

> My favorite quote in this area comes from Jack Vance
> novel. Maybe it was "The Dying Earth." A mixed group of
> pilgrims and travellers were sitting around a campfire, and
> each in turn gave a description of his cosmology. At last
> they turned to Lodermulch, and said, say fellow, you have
> been quiet all through this. What is your idea of the
> universe? And Lodermulch said, "Observe this rent in my
> garment. I am at a loss to explain its presence. I am
> even more puzzled by the existence of the universe."
>
> Followups to comp.databases.metaphysics
>

>>>Okay. It strikes me, though, that this leads directly
>>>to a refutation of the idea that there's any essential
>>>difference between the industry standard external
>>>identifier and the database-specific surrogate key:
>>>it's a matter of context merely, and not anything
>>>intrinsic to that data, or how it is managed.
>>
>>Emphasizing your /only/ in "only in the minds of the users"
>>and /merely/ in "a matter of context /merely/", I'ld say
>>the minds of users and context are as essential as it gets.
>>
>>What would be essential in your view?

Essential to database design.

> We were discussing whether there was a difference between
> the natures of external ids vs. surrogate keys. What is
> essential to this question is what their nature is. Generally
> we do not regard context-specific considerations as essential.

It matters wether data come from the outside or from the inside of the system - the context of the data. Received on Sat Oct 01 2005 - 20:25:00 CEST