I work with design one day to day, and I'll tell you why it's not ideal. If it lacks a single column primary key, some databases, like oracle, make it harder to do an outter join. The way to get around the oracle error is.. 

select
 *
from (
  select
    a.pk1
  from
     table a,b
  where 
     a.pk1 = b.pk1 (+)
) a_outter_joined,b
a_outter_joined.pk2 = b.pk2 (+) and
(a_outter_joined.pk1 = b.pk1 or a_outter_joined.pk1 = null )

[download]
You think you'd be able to do.. 
select
   *
from
   a,b
where
   a.pk1 = b.pk1 (+) and
   a.pk2 = b.pk2 (+)

[download]
Maybe I've assumed that there's a missing single key column that was just left out to make an illustration, but I rather not assume... Oracle 8 generates this error for the above query.

Update: Updated which version of oracle gens the error and which query does what.

----
Then B.I. said, "Hov' remind yourself nobody built like you, you designed yourself"

In reply to Re: OT: benefits of database normalization by exussum0
in thread OT: benefits of database normalization by revdiablo

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