Best alternative to autonumber primary keys

Question

I'm looking for a better primary key than an autonumber data type, namely because it is limited to a long integer when I really need a field to reflect a number or a text string that will never happen again, no question how many records are added or removed from the table. The problem is that I'm not sure how to implement something like turning the current date and time into a hexadecimal string and use this as a unique field that I can use as a primary key.

Am I just too paranoid about the run?

- EDITED 03-16-2010 @ 1237 hours -

I had a person who at the time thought this was a great reference for access-related questions, tells me that replication IDs are just a counter of the number of times the item was replicated ... hence, I never explored it further, After the number of responses, I updated and accepted the answer. I guess I was just a stupid newbie. Seriously though, thanks again for everyone who answered!

Answer 1

GUID They are quite unique.

http://en.wikipedia.org/wiki/Globally_Unique_Identifier

You did not specify your programming language. C # will be something like

String myKey = Guid.NewGuid().toString();

Answer 2

, ? , , 64- . 10 . 100 , .

Answer 3

? AutoNumber, Replication ID Long Integer, 128- , GUID.

, :

, . , , . reset . DST , , .

Answer 4

, . , UUID. , UUID .

, Python:

import uuid
uuid.uuid4()

UUID, : http://en.wikipedia.org/wiki/Uuid

Answer 5

- Autonumber "Random" "Increment". - , , , concurrency .