pg.ddx.io  pgsql-sql@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: katarn <katarn@racsa.co.cr>
To: pgsql-sql@postgresql.org
Subject: Re: Unique key field or serverl fks ?
Date: Mon, 12 Jan 2004 15:36:51 -0600
Message-ID: <40031373.5000305@racsa.co.cr> (raw)
In-Reply-To: <200401120952.53629.dev@archonet.com>
References: <400235D5.1050501@racsa.co.cr>
	<200401120952.53629.dev@archonet.com>


>>Hi,
>>
>>I would like to know opinions about which approach is better:
>>
>>Having a table with a field that works as a unique key, or having
>>several fks that work as a combined key ( all the fks fields )?
>>    
>>
>
>Depends on the particular situation, you'll need to give details of the tables 
>and their place in your system.
>
>There are two reasons I've seen given for using an artificial (substitute) 
>primary key:
>1. It's "lighter" than several other fields (especially where they are text)
>2. The natural primary key has meaning to the users, and the users will tend 
>to get it wrong.
>
>The second is probably the more persuasive - the first can definitely have 
>costs as well as benefits.
>
>  
>
Ok, thanks for answering, example:

    Articles Table
        articleid
    Warehouses Table
        warehouseid
    Locations per warehouse Table
        warehouseid (fk)
        locationid
        description
    Articles Per warehouse
        warehouseid (fk)
        articleid (fk)
        locationid (fk)
        stock

In the Articles per warehouse the "primary key" is  the cominbation of 3 
fks. Is that kind of situation acceptable or it could be better to have 
a unique primary key field in addition to the fks? This "gets worse" if 
another table has information binded to the articles per warehouse, it 
has to reference the 3 fks in addition to its own key fields.

Thanks in advance,

K.




view thread (3+ messages)

Message-ID: <40031373.5000305@racsa.co.cr>
Permalink:  ../40031373.5000305@racsa.co.cr/
Also on:    postgresql.org/message-id/40031373.5000305@racsa.co.cr

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-sql@postgresql.org
  Cc: katarn@racsa.co.cr
  Subject: Re: Unique key field or serverl fks ?
  In-Reply-To: <40031373.5000305@racsa.co.cr>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox