Re: Question about Undo segments

"Howard J. Rogers" <dba_at_hjrdba.com> wrote in message news:<aafd03$9ki$1_at_lust.ihug.co.nz>...
> Undo segments are just rollback segments with a new name. Therefore, what
> was true for rollback segments remains true for undo segments.

But I have seen there are both RBS and Undo Tablespaces in 9i. Which one is used for rollback.
Is data written in both the tablespaces?

>
> Therefore, it's your server process that modifies undo buffers. They get
> flushed to disk as dirty buffers whenever DBWn takes it into its head to do
> any osrt of disk writing. The redo for them is the same as it is for any
> modification to any buffer: the before and after image.
>
> In short, there's nothing magic about them -and if you know how rollback
> blocks are dealt with, that's how undo blocks are managed, too.
>
> Regards
> HJR
>
>
> "Jargular" <zclai_at_yahoo.com> wrote in message
> news:8ae4ae9e.0204270719.22c0f769_at_posting.google.com...
> > Hi,
> >
> > Does anybody know what is the process that writes to the Undo
> > segments? under what condition the Undo buffers are flushed into Undo
> > segments? how are the changes in Undo buffers recorded in the online
> > Redologs? I seached Oracle9i documentation, it seems that they are not
> > detailed in the docs. Anyone can help?
> >
> > really appreciated.
> >
> > Jargular
> > zclai_at_yahoo.com
Received on Sun Apr 28 2002 - 11:27:53 CDT