Skip site navigation (1) Skip section navigation (2)

Re: pervasiveness of surrogate (also called synthetic) keys

From: Rob Sargent <robjsargent(at)gmail(dot)com>
To: Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
Cc: Greg Smith <greg(at)2ndQuadrant(dot)com>, Jeff Davis <pgsql(at)j-davis(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: pervasiveness of surrogate (also called synthetic) keys
Date: 2011-05-03 04:57:29
Message-ID: 4DBF8B39.5030908@gmail.com (view raw or flat)
Thread:
Lists: pgsql-general

Craig Ringer wrote:
> On 03/05/11 11:07, Greg Smith wrote:
>
>   
>> That doesn't mean you can't use
>> them as a sort of foreign key indexing the data; it just means you can't
>> make them the sole unique identifier for a particular entity, where that
>> entity is a person, company, or part.
>>     
>
> Classic case: a database here has several tables indexed by MAC address.
> It's used for asset reporting and software inventory.
>
> Problem: VMs generate random MAC addresses by default. They're not
> guaranteed to be globally unique. Collisions have happened and will
> probably happen again. In this case, it wasn't a big deal, but it just
> goes to show that even the "obviously" globally unique isn't necessarily so.
>
> --
> Craig Ringer
>   

Hm.. Virtual machines as assets.  Mortgage backed securities, anyone.

In response to

Responses

pgsql-general by date

Next:From: Craig RingerDate: 2011-05-03 05:04:22
Subject: Re: pervasiveness of surrogate (also called synthetic) keys
Previous:From: Rob SargentDate: 2011-05-03 04:53:30
Subject: Re: pervasiveness of surrogate (also called synthetic) keys

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group