Re: Primary Key

On: Fri, 23 Nov 2007 09:33:13 +0000, "Peter Childs" <peterachilds(at)gmail(dot)com>
wrote:

> The worse thing I meet is people who think primary keys need to be
> integer single field unique serial fields
>
> I tend to agree that primary keys should be single fields if they
> need to be referenced but should also be natural if at all possible.
> ie use car number plates rather than some serial int.

Why is this desire not better satisfied by an index rather than a key?
Any key into a relation is, in the final analysis, an arbitrary value.
Why is a data value considered intrinsically superior to a sequence?

I am converting a system from HP TruboImage to PostgreSQL and the
framework selected, Ruby on Rails, essentially depends upon the existence
of an integer sequenced primary key for each row. Originally I had a deep
distaste for the artificiality of integer keys but now I really do not
consider them any more, or less, coercive than many other programming
conventions.

Regards,

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