Re: why need to backup undo tablespace?

"Denis Do" <nospam.denisdo_at_yahoo.com> wrote in message news:slrncro61g.rc.nospam.denisdo_at_denisdo.news.google.com...
>> but if you lose undo tablespace and no backup, you still can
>> recreate the undo tablespace.
>

Yes, I did some tests successfully:

1) change undo_management to manual
2) startup instance and drop original undo
3) create new undo
4) shutdown instance and change back to auto

But just like HJR said, no way to test in every kind of scenario.

> Have you tried it? :-)
> Good example - take a kind of big partitioned table, put real load on it,
> run long transaction and start collecting statistics at the same time. :-)
> Yes, it is should not be done like that - but it is happening quite often.
> And kill smon:-) (or shutdown abort)
> And try restore without undo TS:-)
>

For sure instance recovery needs rollback segments, for roll forward and roll back.
You can not recover without undo TS? what's the error msg? you have an rollback
segment in system, right?

> Well, if you still looking for fun and adventures - you can try it.
> If you want to get job done - please do not do it
>
> Have a great day!

I just want to explore why backuping undo is a must, and I could be persuded
easily be an example. Thanks! Received on Mon Dec 13 2004 - 22:24:10 CST