Re: [SQL] arrays

On Sat, 4 Dec 1999, Stephen Davies wrote:
> Arrays do have a role in life: even in a "proper relational" world.
> The classical examples are publications with multiple authors, ISBns, 
> subjects, keywords etc.
> Trying to fully normalise attributes like these leads to nonsensical and 
> unusable database designs.

sorry, that is incorrect.  in a proper system, you don't run out of
``slots''.  say you give each publication an array to hold 3
authors.  what happens when that 4th author comes along, then a
fifth?  you always have a +1 problem.  your database design will stand the
test of time better if you keep a good design.

one may say, ``just put 100 slots for authors''.  then you are just
wasting space.  if you normalize it (in this case store a table containing
the association between a publication and an author), you never hit an
upper limit, and you don't waste space in all those publication tables.

____________________}John Flinchbaugh{______________________
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