Re: maximum number of columns per table

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Thu, 22 Jul 2004 17:58:32 -0700
Message-ID: <1090544337.324561@yasure>

Galen Boyer wrote:

> On Wed, 21 Jul 2004, damorgan_at_x.washington.edu wrote:
>
>

>>But heck who cares about theory ... just write the foreign keys
>>and I'll accept it as the model for my next project.

>
>
> I don't understand your theory here Daniel. Are you saying that
> if a table has to have an inordinate number of columns, you would
> advocate turning to this model of
>
> id, attribute_name, attribute_value
>
> This model is weak in many many ways, but maybe there is, truly a
> good argument for it.
>
> But, here is what I see as the model you are putting forth.
>
> create table customer
> (
> id number
> ,attribute_name varchar2(2000)
> ,attribute_value varchar2(2000)
> );
>
> insert into customer values (1, 'FIRST_NAME', 'Galen');
> insert into customer values (1, 'LAST_NAME', 'Boyer');
>
> Am I missing your point, or are you actually advocating this
> model?
>

No ... as Tony said ... I would assume anyone with a large number of columns is probably naming them things like phone_1, phone_2, phone_3 or budget_2000, budget_2001, budget_2002, etc. which yields to far better modelling vertically rather than horizontally in most cases.

I am most certainly not advocating a VARCHAR2(40) where row1 = First name and row2 = last name. There weren't enough drugs in San Francisco in the 60s for that.

Daniel Morgan Received on Thu Jul 22 2004 - 19:58:32 CDT