Re: sql views for denormalizing

From: dawn <dawnwolthuis_at_gmail.com>
Date: 30 Jul 2005 07:47:13 -0700
Message-ID: <1122734833.220205.102630_at_z14g2000cwz.googlegroups.com>


Lauri wrote:
> dawn wrote:
> > oops, thought I'd correct typo in subject line.
> > dawn wrote:
> >
> >>This is another question on the topic about which I have been most
> >>perplexed -- 1NF.
> >>
> >>Because we want to report against or view data potentially in a
> >>different way than the implementation data model (aka physical model),
> >>we have views. Although we put our base relations into nth normal
> >>form, we don't have such rules for the view.
> >>
> >>Since my interest is in the interface between developer and dbms, the
> >>view might be the area where the RM would have me focus (ignoring
> >>practical issues in working with views such as performance issues).
> >>
> >>IF I am writing a s/w app with a browser user interface showing and
> >>accepting data values that are laid out in a particular order on the
> >>screen, each with a label, then it might make sense to write a view
> >>that matches this web page. I could write a view of the data that
> >>joins, projects and restricts so it includes the desired.
> >>
> >>Does this view need to be in 5NF? No. 4NF? No. BCNF? No. 2NF? No. 1NF?
> >>Yes.
> >>
> >>That's where I get messed up because instead of just showing the view,
> >>I have to massage that view simply because one of the attributes on the
> >>page has cardinality greater than 1.
> >>
> >>If the view is supposed to be the view of the data, then why do we have
> >>this 1NF restriction when we don't care about the other NF's in a view?
> >>
> >>Thanks in advance for your help. --dawn
> >
> >
>
> I don't know if this is relevant to the subject but I gave some time
> ago an example of constructing a fairly complex query with repeating
> values in a column with Dataphor, a supposedly "true" RDBMS. This query
> could be contained in a view.

I saw that at the time, but did not think it aligned with relational databases and thought of it as a .NET effort. I now see that it is based on relational theory, so very good. Are there other implementations that are similar?

>
> See http://www.orafaq.net/usenet/comp.databases.theory/2002/10/30/0482.htm
>
> Note that this example uses an old version of Dataphor.

I'm pretty ignorant of Dataphor, but will look again. I'm running a linux server, and when I see .NET, I kinda glaze over, so if you know of other similar solutions, please pass them along. Thanks!

> Regards,
> Lauri Pietarinen
Received on Sat Jul 30 2005 - 16:47:13 CEST

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