From: Tim Fitzpatrick <tim_fitzpatrick@eircom.ie>
Subject: Re: Designer 6: Transferable relationships between entities
Date: 2000/05/05
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References: <956939703.323161@tbird.introweb.nl>
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In article <956939703.323161@tbird.introweb.nl>,
  "Niels Stout" <n.stout@voltaire.nl> wrote:
> Hi,
>
> Im working with Oracle Designer 6 and I'd like to know what is meant
 by a
> relationship (end) being transferable or not. I've read the Oracle
> documentation but that didn't make things much clearer. When I
 generate my
> database there does not seem to be any difference between checking
 this
> property or leaving it blank. Could someone explain this concept to
 me,
> preferable with an example?
>
> Thanks,
>
> Niels
>
>

Neils,

The transferablility dictates whether a child entity instance can
change parent entity instances over time.

The default in Designer has always been to allow transferability.

The only down side to this is that it should be the other way around,
i.e. relationships should not be transferable. Oracle have known this
for a good few years now, but never done anything about it.

In fact, if a relationship is transferable I would question whether it
should be there at all. I suspect it should be replaced with a many-to-
many resolution entity, containing the effective date attributes hinted
at.

In terms of transformation and generation, the DDL generator has never
done anything with the "transferable" flag. Oracle's argument has
always been that it was there for "future compatibility", or "it seemed
like a good idea at the time".

I hope this helps to clear some things up.

Cheers,
     Tim


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