Re: What are the consequences of a bad database design (never

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От Rafael.Hernamperez@bull.es
Тема Re: What are the consequences of a bad database design (never
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Msg-id OF6EB1237B.E2255968-ONC1256FE0.003611D1-C1256FE0.0036534C@bull.es
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I suggest you make a report identifying these critical points, the current consequences (use, maintenance, performance, resources (hardware, time, etc.)), and a study of the future. Also, expose the benefits of a good design for the future (including the costs of the migration).

Regards,



Rafael Hernampérez Martín
Arquitecto de Bases de Datos
Tecnología, Soluciones e Integración

BULL España, S.A.
Po. de las Doce Estrellas, 2 - 28042 Madrid
Tel. 91 393 93 48 - Fax 91 393 93 22
e-mail:
rafael.hernamperez@bull.es






"Jinane Haddad" <jinanehaddad@hotmail.com>
Enviado por: pgsql-general-owner@postgresql.org

11/04/2005 11:39

       
        Para:        pgsql-general@postgresql.org
        cc:        
        Asunto:        [GENERAL] What are the consequences of a bad database design (never seen that before !)



Hi everyone,

i just got a new job in a small entreprise and they are using postgres as a
database for their application. I was stupefied cause the database design is
so bad : we can even say it has been done by amateurs. I observed the
following problems till now:

1- redondancy ( TOO MUCH)
2- Many tables for the same object (stupid ex: a table for female_employees
another for males ...) instead of one table (there are cases of 6 tables for
the same one)
3- Some essential table are inexistant
4- Null values for critical information
5- Primary keys of multiple fields (4 or 5 sometimes) du to bad design
...

The bottom of the line is that they have been working on the application for
2 years. Querys are becoming bigger and contains a lot of unions and "in/not
in". The data contained in the database have to be checked often invalid
values may be found ...

My question is with such database, what are the lomg term consequences or
can we determinate them. I know that the querys will become slower, and the
database will grow more quickly ... And a lot of information will not be
trust wise ....

But the people i am working with are not considering the restructuring of
the database. They are even thinking of expanding it by adding new modules.

Please can someone advise me, or tell me what to do, what may be the
consequences

Thanx for any help

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