RE: best way to have a unique key

2011-01-21 Thread Jerry Schwartz
-Original Message- From: vegiv...@gmail.com [mailto:vegiv...@gmail.com] On Behalf Of Johan De Meersman Sent: Friday, January 21, 2011 1:22 AM To: Anthony Pace Cc: Michael Dykman; mysql. Subject: Re: best way to have a unique key I have to say, something similar was my first thought, too

Re: best way to have a unique key

2011-01-21 Thread Michael Dykman
One of the components of the UUID is drawn form the mac address of the server.. While in practice this is not true of all systems (except from http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_uuid) Currently, the MAC address of an interface is taken into

RE: best way to have a unique key

2011-01-21 Thread Jerry Schwartz
-Original Message- From: Michael Dykman [mailto:mdyk...@gmail.com] Sent: Friday, January 21, 2011 11:35 AM To: Johan De Meersman Cc: Anthony Pace; mysql. Subject: Re: best way to have a unique key One of the components of the UUID is drawn form the mac address of the server.. While

Re: best way to have a unique key

2011-01-21 Thread Michael Satterwhite
On Friday, January 21, 2011 09:23:47 am Jerry Schwartz wrote: [JS] A UUID (what Microsoft calls a GUID) is based in part on the MAC address of the generating device. Since MAC addresses are supposed to be unique across the known universe, so should a UUID. Not entirely true - and even

Re: best way to have a unique key

2011-01-20 Thread Krishna Chandra Prajapati
uuid() Krishna On Fri, Jan 21, 2011 at 12:02 AM, Anthony Pace anthony.p...@utoronto.cawrote: Due to certain reasons, the company I am doing business with has decided that the primary key, for an orders table, be a unique key; however, I don't like the possibility of it conflicting if moved

Re: best way to have a unique key

2011-01-20 Thread Anthony Pace
Dude, come on. I know that all primary keys have to be unique; however, I was obviously referring to the use of uuid over auto incrementation. On 1/20/2011 1:36 PM, Michael Dykman wrote: It is axiomatic in the relational model that a primary must be unique. This is not a quirk put forth by

Re: best way to have a unique key

2011-01-20 Thread Anthony Pace
I know of uuid() my problem is that there can be conflicts when copying the DB to a different machine, or working with sections of the db on different machines for load balancing. On 1/20/2011 1:44 PM, Krishna Chandra Prajapati wrote: Please keep in mind this variable will also be displayed

Re: best way to have a unique key

2011-01-20 Thread Anthony Pace
Although I did berate you for your obvious cheek, I will of course complement the acuteness of your response. On 1/20/2011 2:10 PM, Anthony Pace wrote: Dude, come on. I know that all primary keys have to be unique; however, I was obviously referring to the use of uuid over auto

Re: best way to have a unique key

2011-01-20 Thread Luciano Furtado
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 What conflicts are you expecting? according to the documentation: A UUID is designed as a number that is globally unique in space and time. Two calls to UUID() are expected to generate two different values, even if these calls are performed on two

Re: best way to have a unique key

2011-01-20 Thread Michael Dykman
I should have read more carefully.. I apologize for my snap response. At a guess: as I recall, under M$ SQLServer the typical (only?) form of unique identifier used is something very UUID-like. MY information might be dated. I was certified as a SQL Server administrator perhaps 12 years agoI

RE: best way to have a unique key

2011-01-20 Thread Daevid Vincent
http://www.mysqlperformanceblog.com/2007/03/13/to-uuid-or-not-to-uuid/ -Original Message- From: Krishna Chandra Prajapati [mailto:prajapat...@gmail.com] Sent: Thursday, January 20, 2011 10:45 AM To: Anthony Pace Cc: mysql. Subject: Re: best way to have a unique key uuid

Re: best way to have a unique key

2011-01-20 Thread Johan De Meersman
I have to say, something similar was my first thought, too - you never mention uuid in your original post. As already stated, uuid() should be a Universal Unique IDentifier. It's afaik a random 128-bit number; given the space to choose from it should be rather unique. I have to admit that I'm not