Re: A pk is *both* a physical and a logical object.
From: paul c <toledobythesea_at_oohay.ac>
Date: Thu, 26 Jul 2007 16:16:28 GMT
Message-ID: <wN3qi.8101$fJ5.4546_at_pd7urf1no>
>
>
>
> Well I think the cat-food problem was specifically about duplicate
> propositions, but yes some of the mistakes in its argumentation are
> related. Not understanding that cans may be recorded individually /or/
> as a whole (depending on what a situation requires) could well be
> another symptom of not thinking in terms of "constructs". I think it
> also might have a lot of other consequences, reaching from why hidden
> OID's are a mistake (we need to be able to identify constructs outside
> in the real world), right through to philosopophical mumbo-jumbo like
> why the "theseus ship paradox" isn't a paradox at all (where different
> people just applying different constructs as in the book example).
>
> I certainly think good db admins often recognize all these things by
> intuition, and experience in designing databases and thats who i've
> picked it up from - but (to my knowledge) it has never been formalized
> at the conceptual level. Oh, and apologies for the wanton use of the
> word "construct". I just don't have a better term.
>
Date: Thu, 26 Jul 2007 16:16:28 GMT
Message-ID: <wN3qi.8101$fJ5.4546_at_pd7urf1no>
JOG wrote:
> On Jul 26, 1:47 pm, "David Cressey" <cresse..._at_verizon.net> wrote:
>
>>"JOG" <j..._at_cs.nott.ac.uk> wrote in message >> >>news:1185445415.561100.98380_at_o61g2000hsh.googlegroups.com... >> >> >>>Just as another example of what i'm on about with this construct >>>m'larkey: Imagine the library has two copies of "harry potter and the >>>deathly hallows". Are they the same book? >> >>This sounds like "the cat food problem" to me. Is it?
>
>
>
> Well I think the cat-food problem was specifically about duplicate
> propositions, but yes some of the mistakes in its argumentation are
> related. Not understanding that cans may be recorded individually /or/
> as a whole (depending on what a situation requires) could well be
> another symptom of not thinking in terms of "constructs". I think it
> also might have a lot of other consequences, reaching from why hidden
> OID's are a mistake (we need to be able to identify constructs outside
> in the real world), right through to philosopophical mumbo-jumbo like
> why the "theseus ship paradox" isn't a paradox at all (where different
> people just applying different constructs as in the book example).
>
> I certainly think good db admins often recognize all these things by
> intuition, and experience in designing databases and thats who i've
> picked it up from - but (to my knowledge) it has never been formalized
> at the conceptual level. Oh, and apologies for the wanton use of the
> word "construct". I just don't have a better term.
>
I can't fault you for preferring a vague term like "construct". Anybody who ventures into the airy-fairy world of conceptual modelling needs their own private armour. I suspect that some conceptual modellers would probably like it, anything to increase the vocabulary and prolong the picture-drawing.
p Received on Thu Jul 26 2007 - 18:16:28 CEST