Re: Beyond the 1600 columns limit on windows

Sorry,
It has nothing to do with normalisation. It is a program for scientific
applications.
Data values are broken into column to allow multiple linear regression and
multivariate regression trees computations.
Even SPSS the most well-known statistic sw uses the same approach and data
structure that my software uses.
Probably I should use another data structure but would not be as eficient
and practical as the one I use now.
Many thanks
-Evandro

On 08 Nov 2005 05:30:07 -0800, Randal L. Schwartz <merlyn(at)stonehenge(dot)com>
wrote:
>
> >>>>> "Evandro's" == Evandro's mailing lists (Please, don't send personal
> messages to this address) <listasjr(at)gmail(dot)com> writes:
>
> [I would have replied to your personal address, but I'm not about
> to copy it from a footer.]
>
> Evandro's> I'm doing a PhD in data mining and I need more than 1600
> columns. I got an
> Evandro's> error message saying that I can not use more than 1600 columns.
> Evandro's> It is happening because I have to change categorical values to
> binary
> Evandro's> creating new columns. Do you know if oracle can handle it?
>
> /me boggles
>
> You are doing a PhD in data mining, and you have a table that needs
> more than 1600 columns?
>
> /me gasps
>
> What are they *teaching* these days?
>
> If you have a design that has more than 20 or so columns, you're
> probably already not normalizing properly. There just aren't *that*
> many attributes of a object before you should start factoring parts of
> it out, even if it means creating some 1-1 tables.
>
> In programming, if I ever see someone name a sequence of variables,
> like "thing1" and "thing2", I know there's going to be trouble ahead,
> because that should have been a different data structure. Similarly,
> I bet some of your columns are "foo1" and "foo2". Signs of brokenness
> in the design.
>
> Or do you really have 1600 *different* attributes, none of which have
> a number in their name? That requires a serious amount of
> creativity. :)
>
> --
> Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777
> 0095
> <merlyn(at)stonehenge(dot)com> <URL:http://www.stonehenge.com/merlyn/>
> Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
> See PerlTraining.Stonehenge.com <http://PerlTraining.Stonehenge.com> for
> onsite and open-enrollment Perl training!
>

--
Evandro M Leite Jr
PhD Student & Software developer
University of Southampton, UK
Personal website: http://evandro.org
Academic website: http://www.soton.ac.uk/~evandro
Please, use Jr(at)evandro.org for personal messages