Re: newbie question about RBS

"wonderinguy" <wonderinguy_at_hotmail.com> wrote in message news:3b20cc63$1_2_at_excalibur.gbmtech.net... >
> Folks, I am pretty new to Oracle. I was under the impression that, once
 all
> the transactions are commited, the roll back segment tablespace would go
> back to 0 % usage + overhead. But it keeps growing and is getting close to
> 100 %. Is this normal ? Or do I have to do something to reset it.

I'm not precisely sure what you mean by "0 % usage + overhead" -- do you mean shrinking to whatever you set as the minimum number of extents? If so this won't usually happen unless you set an OPTIMAL for the rollback segment, which obviously has to be greater than MINEXTENTS. Most things I've read suggest setting MINEXTENTS to something like 10 or 20 & OPTIMAL to be equivalent to that size (assuming your extents are something like 500K or 1M.) This will cause Oracle to shrink the rollback segment back to optimal if it is about to start writing undo in a new extent but detects that the next extent in the segment has no active transactions in it & the segment is greater than OPTIMAL. You can set OPTIMAL with ALTER ROLLBACK SEGMENT... Received on Fri Jun 08 2001 - 16:22:48 CDT