Den 2012-03-06 22:08 skrev Thomas Steinmaurer s�h�r:

>
> > Den 2012-03-06 21:52 skrev Thomas Steinmaurer s�h�r:
> >>
> >> When using a BIGINT feed
> >> by a generator, you can set a starting value per site/server and that
> >> way, you somehow "know" the source of insertion when merging the
> >> satellite databases with a central database.
> >>
> >>
> >
> > Sounds risky and error prone... Better add a source column.
>
> And the source column is feed by what? It can be equally risky if you
> forget to correctly setup that value for the particular site/server.
>
> Just a thought. ;-)
>

I don't think so. Missing source info is a lot less harmful than
duplicate primary keys, which I believe you run the risk of with the
approach you described.

Also, it goes against some rather fundamental principles to encode
information into primary keys. Down that road your feet tend to start
hurting, after a few shots. ;-)

Kjell

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Kjell Rilbe
DataDIA AB
E-post: kjell@...
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