Re: What are the design criteria for primary keys?
Date: Fri, 3 Sep 2010 07:32:59 -0700 (PDT)
On 3 sep, 15:52, Brian <br..._at_selzer-software.com> wrote:
> On Sep 3, 12:20 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> > Choosing good *primary keys* and candidate keys is a vitally important
> > *database design* task--as much art as science. The design task has very
> > specific design criteria.
> > *What are the criteria?*
> > As an experiment, I asked the above question on StackOverflow.com having
> > first verified it wasn't already answered on the site. It is a very
> > important question that has a very simple and clear answer. I had
> > planned to offer a sizable bounty if nobody gave the correct answer
> > after the 1st day and answer it myself if nobody claimed the bounty.
> > Five people identified as John Saunders, David Stratton, Claudio Redi,
> > wallyk, and rockinthesixstring voted to close it with nothing
> > approaching a correct answer supposedly because "It's difficult to tell
> > what is being asked here. This question is ambiguous, vague, incomplete,
> > or rhetorical and cannot be reasonably answered in its current form."
> > I thought the question was clear enough. The answer, of course, is:
> > uniqueness, irreducibility, simplicity, stability and familiarity.
> > To anyone who uses that site as a resource, all I can say is: Caveat lector!
> The answer, of course, is:
> uniqueness, irreducibility, familiarity, and if at all possible,
> simplicity and stability.
> There should be no reason to use surrogates, so I agree on
> familiarity, but not every candidate key is simple, and while
> stability is a worthwhile goal, it is not always achievable.- Tekst uit oorspronkelijk bericht niet weergeven -
> - Tekst uit oorspronkelijk bericht weergeven -
I'm pretty sure Bob didn't mean "100% stability" as a criterion for either-or-not being a key. Received on Fri Sep 03 2010 - 16:32:59 CEST