Re: FOREIGN KEYS vs PERFORMANCE

On Wed, Apr 12, 2006 at 10:36:28AM -0700, Craig A. James wrote:
> Jim C. Nasby wrote:
> >>1. You have only one application that modifies the data. (Otherwise, you
> >>have to duplicate the rules across many applications, leading to a
> >>code-maintenance nightmare).
> >
> >You forgot something:
> >
> >1a: You know that there will never, ever, ever, ever, be any other
> >application that wants to talk to the database.
> >
> >I know tons of people that get burned because they go with something
> >that's "good enough for now", and then regret that decision for years to
> >come.
>
> No, I don't agree with this. Too many people waste time designing for
> "what if..." scenarios that never happen. You don't want to be dumb and
> design something that locks out a foreseeable and likely future need, but
> referential integrity doesn't meet this criterion. There's nothing to keep
> you from changing from app-managed to database-managed referential
> integrity if your needs change.

In this case your argument makes no sense, because you will spend far
more time re-creating RI capability inside an application than if you
just use what the database offers natively.

It's certainly true that you don't want to over-engineer for no reason,
but many times choices are made to save a very small amount of time or
hassle up-front, and those choices become extremely painful later.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461