Re: General question about fk constraints ...

"Niall Litchfield" <n-litchfield_at_audit-commission.gov.uk> wrote in message news:<3e47c303$0$22722$ed9e5944_at_reading.news.pipex.net>...
> "Jan Gelbrich" <j_gelbrich_at_westfalen-blatt.de> wrote in message
> news:b27ql8$1a92b9$1_at_ID-152732.news.dfncis.de...
> > ... that is: about the drive of many software vendors to *avoid* them ...
> >
> > Hello !
> >
> > Just as a matter of interest, I would like to know *why* are so many data
> > models implemented out there
> > are neglecting fk constraints to a degree that it makes me almost mad -
> > sorry ...
> >
> > When I was trained in ER design 1 and 1/2 year ago,
> > we were told never to sacrifice fk constraints for the douptful sake
> > of performance,
> > and we set up easy-to-read ERMs with countable table numbers and so on ...
> >
> > Now, on my working place I see (and from many others I hear) that it seems
> > very common
> > *not* to use constraints, just for the sake of performance - all the guys
> > around me say that, and they are
> > just asking "R U kidding ?! *Why* for *** sake do You wanna use
> constraints
> > ?! *You* as dba shoulda known better ... "
> > which makes me almost speechless for a moment 8|
>
> Any production DBA who thinks that performance is more important than data
> integrity has a rather large problem, IMO. FWIW I don't believe that the
> true reason for this trend has anything to do with performance, but does
> have everything to do with speed of development. If you can cut out the
> constraint definitions, logical design and correct transaction definitions
> from your app you can probably develop it in half the time.

I think this is the better half of the explanation. The other half is historical compatability. While one might think that reverse-engineering and adding the constraints would help, there are so many data elements in a large system, and so many programs written to the old system, that it is just too huge of a job, even for Oracle corp. It winds up taking years, so you have to deal with a moving technology target. And as someone else has posted, other than Oracle Apps there's the cross-db compatibility issue.

>
> RAD when it means Rapid Application Development is good news, Rapid Aircraft
> Development seems not to be an acronym - I wonder why.

Of course, some people think RAD is bad news :) (I'm coming from somewhere in the middle of RAD and formal design).

Hey, 100 years ago do you think the Wrights used RAD (I guess it would be RED) to build the Flyer? :)

jg

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