Re: Concurrency in Oracle!

In article <36147A48.C26E9858_at_slagehs.dk>,   dm2101 <dm2101_at_slagehs.dk> wrote:
> Hey,
>
> Does anyone know where it is possible to find specific information on
> which concurrence and recovery methods Oracle use????
>
> Or does anyone know anything about it??
>
> Thanks in advance...
>
> Lars Søe
> Denmark
>
>

Oracle uses a technique called Multiversioning. It is described in their manuals (check the DBA or Server manuals. I forget the exact titles and I don't have my copies handy. (my copies are still version 7.0) The basic concept is that any rows of a table being updated by one session and involved in a query by another session have their values for that query session moved out to rollback segments until that query completes. The advantage is no locks so readers and writers do not interfere with each other.

Maybe you should visit the oracle web site and ask for more information. (Let me know if you need more help. I have a report I wrote on this somewhere.)

Have a good day.
  ed

--
Ed Prochak
Magic Interface, Ltd.
440-498-3702

-----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own Received on Fri Oct 02 1998 - 10:34:04 CDT