Robust unique identifiers?

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. Received on Fri Jan 21 2005 - 16:11:21 CST