Re: Robust unique identifiers?

Pete wrote:

> Hi there ... after much research i still can't quite find the right
> answer to this problem, so here goes.
>
>
> I'm trying to find a simple, robust and scalable way to manage unique
> identifiers in my database system. The system generates paper forms
> containing the UIDs and sends them to customers, so maintaining
> integrity of the numbers is critical.
>
>
> The system needs to be non-DBMS-specific, needs to be able to run in
> multiple instances simultaneously (although this is only a
> hypothetical, later requirement) and needs to be as robust as possible
> throughout DB restores, general maintenance and against rogue DBAs
> resetting IDENTITYs and the like.
>
>
> I've been looking at generating a unique key using a hashed combination
> of the server ID and a low-level timestamp, which is fine except that
> it generates enormous numbers. Customers need to be able to quote the
> numbers easily to call centre staff, so I'm looking for something
> ideally no more than about 12-16 digits. Is there a quality random
> value generator that will give numbers as short as this? Or, is there a
> suitably robust way of using SQL IDENTITYs to achieve what I need?
> Many thanks for any help.
>
>
> Pete.

Can't find anything in Sybrand's comments to disagree with.

For every developer that thinks he can create something that is non-database specific ... there are two people being paid by the hour to clean up the mess later.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)