Re: Generating Sequence Numbers

From: <markp7832_at_my-deja.com>
Date: Wed, 22 Sep 1999 15:27:31 GMT
Message-ID: <7sasgh$d6j$1@nnrp1.deja.com>

In article <7s921q$3ud$1_at_nnrp1.deja.com>, Kevin Mackie <mackster_at_my-deja.com> wrote:
> Is there a non-platform specific way to generate sequence numbers
using
> only SQL?
>
> Apologies for the non-Oracle specific question in this forum, but it
> seemed like the best place for it.
>
> Thanks,
>
> Kevin
>

Yes, however the reason most rdbms vendors provide a sequence generator is because the only way to generate a sequence with just SQL is to use a table row column as a counter which then requires a 'select for update' type query to prevent multiple processes from reading the same value. This creates a lock wait situation where all users of the sequence have to wait for the prior transaction to complete with a commit before they can get a number. This is not acceptable for most applications.

You can try the comp.databases.theory newsgroup for a second opinion.

--
Mark D. Powell -- The only advice that counts is the advice that you follow so follow your own advice --

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Share what you know. Learn what you don't. Received on Wed Sep 22 1999 - 10:27:31 CDT