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From: billc@blia.UUCP
Newsgroups: comp.databases
Subject: Re: Normalized Databases
Message-ID: <2146@blia.BLI.COM>
Date: Tue, 14-Apr-87 16:34:57 EST
Article-I.D.: blia.2146
Posted: Tue Apr 14 16:34:57 1987
Date-Received: Thu, 16-Apr-87 00:35:22 EST
References: <43239@beno.seismo.CSS.GOV> <2010@blia.BLI.COM> <2870@well.UUCP>
Distribution: na
Organization: Britton Lee, Los Gatos, CA
Lines: 23
Keywords: normal form, relational
Summary: just another note...

The point of my earlier posting was simply that there is no formula that
can replace common sense in designing a schema.  There are people who
are religious about normalization in the sense that they believe in
rigorous normalization no matter what the situation.

I suppose it IS easier to explain a normalized database, given a high
level of complexity.  I was thinking, though, about tutuorial level
indoctrination into query languages.  I'll take a concrete example:
it is very hard to explain correlated subqueries
to the poor first-time SQL user.  (And indeed, they are a horrible botch.)
When describing correlated subqueries, I like to start with single-table
examples.  If the example schema is normalized, the simplest "sensible" 
example query may have 2 or 3 joins involved.  This adds a lot more "noise",
and makes the examples a good deal more difficult to comprehend.
Certainly, once a user understands the query language
a somewhat-normalized database can be easier to understand, but again,
the normalization should be pursued with common sense rather than
with formulaic rabidity :-).
-- 
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