Re: Table Design!

From: DA Morgan <damorgan_at_psoug.org>
Date: Wed, 16 Nov 2005 06:55:09 -0800
Message-ID: <1132152911.199838@yasure>

gazzag wrote:

>>>Except that a sequence, as demonstrated, actually won't on a
>>>multi-user system.

>
>
> Yes it will. That sequence will give you numbers in ascending order
> which is what the OP asked for. Whether they're sequential or not is
> irrelevant.

A common belief but not necessarily true.

A sequence, by default, caches 20 numbers in memory. The order in which those numbers are retrieved from memory is not guaranteed to be in ascending order ... or any order.

It is true that during testing on stand-alone single-user instances they always are. But go to a multi-user system with high-activity and your mileage may vary.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)

Received on Wed Nov 16 2005 - 08:55:09 CST