sql views for denomalizing
Date: 29 Jul 2005 20:01:19 -0700
Message-ID: <1122692479.482170.221750_at_z14g2000cwz.googlegroups.com>
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
Received on Sat Jul 30 2005 - 05:01:19 CEST