Re: Nested Relations / RVAs / NFNF

"Kenneth Downs" <firstinit.lastname_at_lastnameplusfam.net> wrote in message news:1giplc.ush.ln_at_mercury.downsfam.net...
> Dawn M. Wolthuis wrote:
>
> > "Marshall Spight" <mspight_at_dnai.com> wrote in message
> > news:Z0Rfd.258396$wV.95677_at_attbi_s54...
> >> "Kenneth Downs" <firstinit.lastname_at_lastnameplusfam.net> wrote in
message
> > news:7dfolc.m6e.ln_at_mercury.downsfam.net...
> >> > Marshall Spight wrote:
> > <snip>
> >> > Those who dislike surrogate keys are probably turning green at the
> > thought.
> >>
> >> Heck with 'em. Surrogate keys are a fact of life. (Which doesn't mean
> >> natural keys aren't "better"-- but sometimes you don't have a natural
> >> key, and you gotta have *some* key.)
> >
> > Another byproduct of embedded lists is that a larger percentage of
primary
> > collections (e.g. relations) have natural keys. Many of the relations
> > that would otherwise need surrogates can be nested and don't need
foreign
> > keys
> > from the parent to the child. --dawn
>
> How do you apply referential integrity to the individual members of a
list?

Part of the RI is handled simply by having the list be an attribute of a parent structure. If the parent goes away, the list does too. If you need additional RI, such as if it is a list of foreign keys, then you must identify this fact. I don't know how any particular RDBMS does this, if it is done, but it isn't conceptual complex. --dawn Received on Thu Oct 28 2004 - 04:12:01 CEST