Re: Navigation vs Relational operators

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"Gene Wirchenko" <genew_at_mail.ocis.net> wrote in message news:99bga0l4713o8g0r5krejq7ldchniifrgh_at_4ax.com...
> "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote:
>
> [snip]
>
> >I dunno about that -- it seems to me that if you say "Take me to LAX" and
> >you take me down all of these streets until we get there -- that is
> >navigation. I didn't need to know how to get there, but someone did.
> >
> >If you say "Take me to LAX" and you don't navigate there, but rather use
> >some set operations to beem me up to LAX, then that is relational -- no
> >visible navigation because no navigational operators were employed by
anyone
> >including the taxi driver.
> >
> >Or am I missing the point? --dawn
>
> I think so. In the second case, the transporter operator would
> know what to do. In the first case, the taxi driver is analogous to
> the DBMS. In the second case, the transporter operator is analagous
> to the DBMS. In both cases, we do not need to know how they do what
> they do; we just specify the desired result.
>
> The navigation (or whatever the execution is called) is hidden
> from us.

Well, we don't need to tell the driver how to drive. But we may need to tell him (some of) the route ...

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