Re: Rollback Segment Setup Questions

You usually create 4 segments? That is ludicrous. There is no magic number for all database or even a good portion.

In general 1 rollback segment per 4 users is a good "starting" point. I make them all the same size, with proper next value, 4 extents, and optimal 4xinitial value. Then depending on ratio get/wait and other things I increase / decrease. Size is dependant on the load and transactions.

I also create large rollback segment or two for batch jobs or specific reasons, it isn't always online either.

So saying use x amount of rollback segments I don't believe is much use. Like a lot of settings you can only get a starting point from any book, proper sizing is "tuning" and tuning takes trial and error. Good starting points make it less trial with less error.

Just my 48 cents.

On Thu, 24 Feb 2000 04:22:05 -0800, Martin <mhaNOmhSPAM_at_maconomy.dk.invalid> wrote:

>Hi there
>
>I might have some pointers..
>
>If you make a Oracle installation i usally create 4 rolback
>segments, same size.
>
>your question concerning the mix between system and public
>rollback i dont understand. If you have you rolback
>segments are online you dont need a publick rollback ! .
>
>The sizes of the different tablespaces System, rollback
>depends on the installation you are doing. if its personal
>use then not too big ... on the other hand if its a
>installation for a customer they should be quite large.
>
>hope it helps
>
>B regards
>Martin
>
>
>
>
>* Sent from AltaVista http://www.altavista.com Where you can also find related Web Pages, Images, Audios, Videos, News, and Shopping. Smart is Beautiful

Christopher Spence
Senior MIS Engineer
A+ CNA Raptor Received on Thu Feb 24 2000 - 21:25:55 CST